Basement Conversion
Basement Conversion
Basement Conversion
About us
Among the top residential architecture firms in London, Scenario Architecture has built a solid reputation expanding and enhancing homes across the city. Our architects distil the ambitions of today’s homeowners into hard-working houses that express the past and look to the future. We specialise in striking interiors that maximise space and welcome natural light. The Scenario client aspires to a new archetype for London living: open, comfortable and luxurious yet accessible.
We founded Scenario with an ambitious mandate: to adapt our signature style to the needs of a growing family. We collaborate every step of the way with our clients to create highly functional interiors that make the best use of their investment. Scenario’s bespoke architecture tells the story of the homeowner, not the architects.
Our portfolio of new and heritage properties includes Scenario House, an East London terrace house we expanded in nearly every direction to accommodate the busy and evolving lifestyle of its owners. In 2018, Scenario House was shortlisted for several prestigious prizes, including the RIBA London Awards.
Your Basement Conversion project
We’ve drawn up this illustrated overview to help you understand each stage of your home renovation and extension. And we’ve created a step-by-step guide to help see you through the planning permission process. It deals with the ins and outs of UK planning and offers strategies for navigating the system, based on our own successes.
Most home extensions and basement conversions require planning permission from the council in question. Scenario has been successful in securing this permission on behalf of our clients.
Tip
Discover if your architect has had success steering planning applications through your local council. Visit the “planning applications” page of your council’s website and enter the architect’s name in the search criteria.
Basement Conversion
Basement Conversion
Scenario is an established architecture practice focusing on contemporary residential design. We take on projects of every scale and scope, from home refurbishment, renovation and expansions to new-builds.
Working with Scenario Architecture
Our boutique architecture practice specialises in home expansions of every scale and complexity. We offer a truly bespoke service, collaborating with homeowners on every stage of the process, from the initial designs to the project’s completion.
All our architects are fluent with the latest 3D design and visualisation tools. They use real-time visualisations and virtual reality to choose finishes and fixtures, maximise living space and simulate natural light. Our construction information comes from accurate 3D building information modelling (BIM) technology that saves the client time and money. This case study from the Chartered Institute of Building (CIOB) demonstrates the benefits of advanced technology for domestic architecture.
Scenario is a RIBA Chartered Practice, complying with the strict health and safety measures of the Royal Institute of Chartered Architects.
Basement Conversion
In our client's words
Basement Conversion
Great ideas and vision to help with our substantial improvement of a Victorian terrace. In our experience Scenario's method prioritises the final result. That may mean more professional fees or higher quotes from contractors, as they understand the exact requirements.
Basement Conversion
Great, professional service. Good drawings and models and ultimately passed planning at the first attempt with Hackney Council. Would certainly recommend!
Basement Conversion
Scenario Architecture have created an outstanding design and space that was beyond my expectations. The design was through their unique process of understanding the client’s daily scenarios and collaborating with the client to come up with a unique design. The design process is one of the most memorable parts of the process and they also stretched my existing ideas to help create this unique space. A stress free journey throughout the whole process which Scenario were indispensable by giving advice on many difficult design and build decisions.
Basement Conversion
We wanted to renovate our house in a conservation area in central London. Given this involved a complete demolition and new build with an extra floor on top, getting planning approval was always going to be tricky. Scenario did an amazing job on the new house 'envelope' and throughout the planning phase. We couldn't have wished for better from them and having succeeded in gaining planning approval owe them a very big 'thank you'.
Basement Conversion
Scenario were great at thinking imaginatively and coming up with a design for a ground floor extension that was more ambitous than other architects we spoke to. They also helped us find a contractor who was able to complete the project working within timescale and our tight budget. I would recommend for mid to large sized projects with sufficient budget to allow for full utilisation of their creativity.
Further Reading
Basement conversions have got a bad rap over the years, from households digging down multiple levels and edging dangerously close to their neighbours’ property lines. These “mega-basements”, or so-called iceberg houses, cause controversy for their deluxe features, like swimming pools, cinemas, wine cellars Turkish baths and car parks.
Building below street level can significantly increase the size of a home where conservation laws restrict expanding up and out. And new rooms below the main floor almost always make financial sense in high-value areas like London. But the more commonly sought and approved versions seek to enlarge an already existing coal hole or cellar. Even the most basic below-ground extensions will cost the same as a loft conversion, yet they’ll provide far more space for the outlay – most basement conversions in London start at about 40 square metres in size, growing to nearly 200 square metres.
Most basement conversions will require local Building Regulations approval, a sign-off from the neighbours and savvy planning. As most existing subterranean spaces lack any significant head height, most require excavation and underpinning. The height of the water table and location of sewer drains are an issue. And if the space lacks any access to light, a lightwell, an opening in the home’s entryway or glazing in the interior stairwell will need to be considered. If your basement conversion forms part of a larger all-over renovation, you can fold the assessment and application costs into your overall budget.
All that aside, converting a basement makes sense for families that intend to stay put and use it. Anyone looking for extra storage space, a separate playroom for growing children or a tucked-away space for utilities will find all these can be covered off in a single excavation. A well-planned basement can be the difference between staying in a beloved city home or leaving for the outskirts.
To make the most of your investment, you’ll want to consult an architect well versed in the local building codes and permissions protocol, and experienced in converting the vernacular architecture. If your home dates back more than a century, an architect that deals in period properties will be able to assess ballpark costs and potential risks with a single meeting. A good architect will be on hand throughout your project, overseeing quality control and serving as a liaison until the basement is properly executed.
Advice
View AllFrequently Asked Questions
- As a dynamic practice operating in London’s premium residential market, managing projects remotely and conducting virtual meetings was a very familiar territory for us, long before the pandemic began and ‘working remotely’ became the norm.
- Our clients have very busy lifestyles and may move between several different locations, both within the UK and beyond, during the lifecycle of a typical project.
- To accommodate such client needs and enable us to run their projects smoothly we had all the technology and know-how associated with remote working in place for several years.
- Read our full (Virtual) Process
- Scenario based design – We start each and every project with a meticulous analysis of our client’s vision, requirements and aspirations. We do this by asking our clients to imagine their everyday scenarios living in the completed house and describe their desired interaction with it.
- Uniquely interactive - Our client’s deep involvement in the process does not stop with completion of the brief. Our design meetings are highly interactive, informal and fun.
- Designed to reflect you – Based purely on your lifestyle, aspirations and requirements and free from externally imposed concepts, metaphors and pre-conceptions, a completely fresh and unique design will gradually emerge and it will tell your story not ours.
- Collaborative – We start the conversation with planners early and advise most of our clients to seek pre-planning advice prior to submission of a full planning application. Our experience shows that when properly consulted and liaised with, most planning case officers will be receptive to conduct a professional dialogue, increasing chances of successes.
- Strategic – We tailor a custom planning strategy for each project based on its circumstances such as planning history, local context and specific challenging elements. We sometimes split applications or introduce minor tweaks to the scheme during the consideration period in conversation with the officers to prevent one contentious element from jeopardising approval of the main scheme.
- Professional – Our experience shows that the quality and clarity of the submission in terms of background research, planning history of the property and context, precedent and of course the arguments presented to support the case has a tremendous effect on success rate.
- The decision period clock only starts ticking once the application is validated by the Council, This requires then to check that the forms are completed correctly and that the submission contains all the necessary drawings, statements and reports.
- Although required by law to provide a decision within the statutory eight weeks period, it is not uncommon for councils to miss the deadline of the consideration period, normally only by a few days, sometimes longer.
- In some cases the council may ask us as your agent for an extension of time, this may be requested due to internal reasons or as an acceptable result of a professional discussion that we are conducting with them about certain aspects of the application that they are not sure about.
- Our experience shows that planning officers respond better to projects when they feel consulted and collaborated with. We find that when we truly listen to their often helpful and valid feedback and treat them as consultants for the projects and not representative of an evil enforcing authority, they tend to collaborate well with us and demonstrate increased flexibility.
- Although the council in theory have eight weeks to consider your application, in practice they are constantly overloaded. They will only look at your application in the last few days of the consideration period. If this is the first time that they come across a scheme that they were never consulted about, our chance to secure permission for you in a single attempt is significantly compromised.
- The standard practice is for the council to consider the full planning application as submitted and then issue a yes or no decision. Case officers are not required or even encouraged to enter a discussion with us or accept resubmission of minor changes to the proposed scheme during the consideration period.
Planning a basement conversion project? Here’s what to expect and eight design considerations.
If you find yourself wanting more living space but unable to move to a larger property, a basement conversion may be the perfect solution to gain extra space.
If your home has unused or unfinished basement space, converting it into a new living space can be a great way to increase the value of your home and expand the square footage of your home to accommodate family, friends, or out of town guests.
Depending on the room’s size and layout, your options for using the space will vary. A large, open space can be divided into several smaller sections for a bonus living room or game room and also incorporate a kid’s play area or extra office. Smaller basements may be a good size for adding on another bedroom or bonus room. Other basement uses include a fitness or sauna area, a nanny or in-law suite, in-home movie theatres, and even a swimming pool!
Planning your conversion
The first step in converting the basement is to have an architect create a design to achieve the outcome you want. When choosing an architect, ensure you’re working with one that is well versed in the local building codes and permissions protocols. Nearly all basement conversions will require navigating the planning permissions process through the local council. Depending on the extent of the renovation, you may also need additional building regulation approvals.
Take your time to do some research on potential design ideas. For a project of this size, it’s critical to consider all the factors ahead of time and be confident in what you want or don’t want from your architecture renderings. The more specific you can be in the early stages of the project regarding measurement, design, and features, the more likely you’ll be to avoid extra costs down the road.
Once you have your design in hand and an experienced architect on your site, you’ll be able to plan the timeframe for the project, establish a budget, and plan for other tasks like waterproofing the space. Depending on the size of the project and the extent of the basement conversion, most projects will take anywhere from 12-24 weeks to complete. Thankfully, most people can remain in their home during the project as most builders will create and use a separate entrance/exit to access the space.
Next, you’ll want to do some double-checking of the basics before you get into building something new. You may want to add plumbing and wiring to your basement, including a separate bathroom, depending on the size of your home and intended use of the basement space. Check on existing systems to see what expansions and upgrades need to be addressed before construction begins. Converted basement spaces often require added insulation to protect against noise and help regulate the temperature.
Addressing other sometimes overlooked issues like ensuring windows for fire safety and exits, proper ventilation, and considering adding a sump pump in the house is located in a place where groundwater could be a moisture threat are all items that should be considered early in the renovation process. And remember that moisture isn’t just a potential indoor issue. Install diverters to send gutter water at least 10 feet from the foundation and slope soil away from the foundation, as well, to prevent any flooding or moisture seeping in from the outdoor spaces. It’s also essential to have a professional check fuel-burning equipment and your house’s ventilation system to ensure that you won’t have carbon monoxide buildup below grade.
Design considerations
Try to configure the space with as much natural lighting as possible by either enlarging windows or adding a glass-door walk-out area.
When choosing artificial lighting, opt for warm lights in ceiling fixtures and lamps to create a cosy atmosphere. Can lights are also great choices as they provide a significant amount of light but fit neatly up in the ceiling and accommodate nicely for lower ceiling heights.
Choose light paint colours that make the room feel more expansive
Greys, beiges and even whites are popular paint choices for basement areas that often feel cramped or closed in when dark colours or busy wallpaper patterns cover walls.
Use partitions instead of adding new walls, where possible
For basement spaces with low ceilings, adding new walls might make the area feel even smaller. If the new living area is a multi-use area, using attractive and moveable partitions will help keep the space feeling bright and open. Another solution here is to build half-wall dividers or walls with window cutouts so that light can penetrate the interior.
Upgrade the electrical components
Many basements do not include sufficient electrical outlets, so homeowners should factor this into the project in the early stages.
Think long term
While you might not have children at the time of construction, building in an additional area for a playroom or jungle gym will allow you to plan for the future and be an attractive selling point when you are ready to sell the home. Long-term planning also applies to other features like mini-kitchens, laundry areas, and additional bathrooms.
Get smart about storage
Get creative with storage by using a pull-down Murphy bed in the bedroom area, built-ins for bookshelves or games, and window benches to hold extra linens or blankets.
Add a private entrance
A basement walkout is a must for homes that have enough outdoor space for a door and walkway. This additional exit from the basement is an excellent feature if you’re considering using the area for a renter or guests that would appreciate their own entrance/exit.
Don’t forget the stairway
Basement stairs tend to be narrow and dark, which will take away from your newly renovated living space. Add a sturdy handrail, additional lighting, and freshen up wood stairs for a great first impression into your freshly converted basement.
Basement conversions are a huge undertaking but one of the best financial investments a person can make in increasing the value of their home and the enjoyment of their living space. Working with an experienced architect from the very beginning will take much of the stress out of the process and ensure you have trusted guidance from start to finish.
How To Get Planning Permission For Conversion Projects
If you’re ever hoping to ever improve your home and turn it into something a lot prettier and more valuable, then a conversion will always be an option that is popular with the majority. This option will not only help you regarding awkward and restrictive planning policies but will also inject a lot more zest and good looks to the exterior and interior.
On the surface, turning one area into something entirely new might seem pretty straightforward – there are a few bumps in the road, however. Let’s have a little chat about what planners allow and what options are available going forward.
The Kinds Of Conversions Around
There are plenty of different kinds of properties that can be turned into something new and extraordinary. Whatever you can think of, there will be an opportunity to convert and change things around. Chapels, schools, pumping stations, equestrian buildings, and so many others will be allowed to be worked on. Pretty much every type of building could be capable of conversion into a unique contemporary home.
The Basics Of Planning This Kind Of Work
All kinds of conversion will require some kind of planning. Some will benefit from permitted development rights (PD rights), however. This means they’re able to go ahead without the need for a formal planning application. It’ll be pre-approved, provided that the scheme meets certain criteria already.
PD rights are rights to convert the likes of agricultural buildings and offices. This determines the suitability of a building for a conversion, a procedure known as Prior Approval is involved. This means you’ll have to submit a form to the council in the same way you would with a planning application. The considerations by the council regarding Prior Approval are more limited, however. They’ll take into account the transport, highway, noise, flooding, contamination, and if the location itself is suitable. The external appearance and whether it changes a little too much will also matter. You’ll also have to make sure the internal rooms will have enough natural light.
If a planning application is required, then it has to be in detail. The application has to cover both the physical work and the change of use to residential property. The building will have to be capable of being converted with an extension or a rebuild.
Whenever you assess a project, you have to take into account the access, the garden, outbuildings, and parking areas.
Projects That Require Formal Plans
With regard to converting the likes of a rural property, PD isn’t the only route. If your project isn’t allowed via the parameter set, you’ll be able to make an application for full planning. The chances are that your district council’s Local Plan will possess a policy that handles conversions of all kinds.
A lot of local plans have a bias towards the reuse of rural businesses and other business properties for business purposes. This includes tourism-related uses like holiday lets, in preference to residential conversions. With that said, it’s often necessary to demonstrate that alternative uses wouldn’t be viable as part of the justification for conversion to a dwelling. Plenty of other policies require marketing to take place for a while in order to prove there’s little-to-no demand for non-residential use.
The Possibilities And Pitfalls Of Conversions
When submitting a conversion application, you have to send in a structural survey in order to show that the building is able to be worked on with a rebuild being necessary. A lot of the time, there will be structures that are either too decrepit or too flimsy for this to be possible. The likes of rural buildings can provide a habitat for protected species, and any application to convert is likely to be accompanied by a survey that will determine their presence. The presence of things like bats wouldn’t typically be enough to prevent a building from being converted – it will likely add time and cost, however.
Another awkward instance in this regard comes from the fact that contaminations may appear – especially if you’re in the countryside and on farms or industrial land. Again, surveys and analysis will take place in order to determine the right steps, which will, again, add to the fee and add more time to the project.
Design Considerations
When converting an old building, the council will want to preserve as much of its original character as possible. This will include the limiting of inserting new structural openings and avoiding things that disguise it from its original form and purpose. What’s acceptable depends entirely on the likes or dislikes of the council’s design and conservation team. It would be wise to check out other conversion permissions in nearby areas to see what has been approved in the past. Some will want things to be kept very similar, and others might be a little more lenient in terms of styles. If you have a particular style in mind, you should do what you can to look for a building in your area that is likely to be accepted.
Consent And Conditions
Even if things are approved and ready to begin, you will still have to deal with plenty of conditions along the way. It’s common for restrictions to be imposed further on down the line, too. The council will look to achieve this by removing permitted development rights regarding extensions and alterations to the building – as well as the right to put up outbuildings in the garden.
With the removal of PD eligibility, it doesn’t mean you cannot do things at a later date – it does mean, however, that you’ll have to get planning permission for them. Remember also that, when converting, you’ll have to make sure you don’t demolish anything that you do not have permission to remove.