Cellars in many houses have been left unoccupied. They’re most likely dark, wet, and dank, making them unsuitable for storage or even spending any amount of time in. A basement conversion is a process of converting this area into a habitable room. There are various degrees of basement conversion, ranging from a fundamental transformation to one that includes excavation and extension to provide adequate height for human habitation.

What is the Purpose of Your Basement?

There are several compelling reasons to convert your basement. The main reason is that they allow you to have more room, which is close to the other living spaces in your house. This makes it ideal for families searching for extra living space, first-time buyers in a home that lacks space, and individuals who have downsized and are looking for a place for everything.

Increasing property prices are also encouraging individuals to wait longer before purchasing a place of their own, as they save to acquire a home. Basement conversions are an excellent option, allowing kids to have their living areas. Alternatively, you may turn this private area into an additional living space for elderly parents.

Converted basements are also ideal for storage, freeing up valuable above-ground space. More and more people are interested in keeping fit, and home gyms are convenient for those who wish to work from home or be self-employed.

How long does it take to convert a basement?

The amount of time it takes to convert a basement is determined by what you want to accomplish and the size of your basement space. Converting a basic single-room subterranean chamber with a waterproof membrane cavity system (more on this later) might take as few as two or three weeks, including excavating the sump and installing the pumping system. Converting and extending the cellar, lowering the flooring, and so on can last for several months. If you’re unsure when you should start working, consider doing it in the summer. Contact DBI for more information.

Is it possible to convert a basement without hiring an expert?

There are several DIY basement conversion tasks that you can accomplish, but there are others that will most likely need the help of specialists. It all depends on your skill level and the type of basement conversion project you’re working on. Our basement conversion guide covers everything, so you’ll know what each component is and whether you’ll be able to do it yourself to keep expenses low.

Planning Permission and Building Regulations

Before you start a basement conversion, check with your local authority to see if planning permission is required. If you hire a professional basement contractor to supply a design and build service, they will take care of everything, including if necessary, Building Regulations approval and Party Wall Agreements. Read our list of questions to ask basement contractors to help you pick the finest company for the task.

Planning Permission for Basements

When converting an existing basement or cellar, in most cases, planning permission is not required. When you convert an existing cellar to a living area, it just needs a “change of use,” so there is no need for planning permission. According to the Government’s Planning Portal: “When adding a new basement, increasing the size significantly, or when ‘the usage is drastically changed or a light well is added,’ which changes the external appearance of the property,’ planning permission is required.”

If you want to raise the ceiling height of a cellar by lowering the floor level, this will most likely need planning permission. Small extensions and changes are permitted under Permitted Development Rights. Also, if you reside in a heritage property, you’ll almost certainly need consent for interior or external work.

Include the following in your letter: “Confirmation that I may go ahead with the work would be appreciated. It’s useful to have proof that planning wasn’t required when and if you sell your home. n” Send a copy of this letter by certified mail, return receipt requested, so there is no room for error.

Building Regulations for Basements

Even if a basement is simply converted into a usable area, it will need Building Regulations approval. Even if you only change the use of an existing cellar, Building Regulations will ensure that your newly transformed basement is safe and energy-efficient.

The Building Regulations apply to topics such as fire escape routes, ventilation, ceiling height, damp proofing, electrical wiring, and water supplies. The Basement Information Centre has created new information on this topic. More information may be found on their website.

The repair of a subterranean area that is already used for habitation, or the conversion of a non-habitable basement into a living area does not require Planning Permission under Building Regulations.

Fire Safety in Basements

The Building Regulations contain information on fire safety, including the need for basement fire escapes. There must be a ‘suitable means of egress in case of fire from the building’ according to the Regulations. The Regulations first define a basement level and then go on to outline whether or not the basement is an inner room or a separate fire-resistant structure.

Party Walls

If you own other properties that adjoin yours and share walls that will be affected by the conversion, you must follow the Party Wall Act 1996. You’ll need to communicate with the property owners and tenants on the other side. A Party Wall Agreement for each neighbour will cost £700.

Basement Flooding

How can my basement flood?

If your basement is damp, identifying the source of the water might be difficult. You are more prone to flooding if you don’t know what caused it. Low-lying locations, especially those under the flood line, are more vulnerable.

Basement Waterproofing

The goal of most basement renovations is to provide more liveable square footage while also keeping it dry and pleasant. The process of waterproofing a basement is an essential component of any basement conversion.

Water won’t be able to enter your basement if you block its passage. External waterproofing and cementitious tanking (these work by blocking the passage of water into your basement) are two options for preventing water from reaching your basement, or you can install a cavity membrane drainage system that allows you to control any water ingress by sending it to an appropriate evacuation point.

What is the best way to waterproof a basement?

Choosing the best waterproofing technique for a basement requires an understanding of the many waterproofing methods and how they interact. It should also consider the intended usage. The three primary sorts of basement waterproofing are outlined in the table below, which may be utilized together to form a successful solution.

External waterproofing: Basement waterproofing of this sort is usually done in the construction of a basement or below-ground structure. It is based largely on a planned building method and the use of moisture-resistant materials. Unfortunately, despite the waterproofing system being tested to completion only when the basement or beneath the ground structure is completely backfilled and the earth around the location has settled, this form of waterproofing may result in water intruding into a previously dry environment.

Tanking: The process of waterproofing or tanking a basement entail laying a fully bonded waterproof cement system on the walls, floors, and occasionally ceilings. The tanking solution then adheres to the existing masonry substrate, forming an impermeable layer that prevents water entry while remaining breathable. Tanking is intended to resist external water pressure around the basement and must therefore be completely attached to the substrate. Any fault in the tanking will become apparent when external pressure drives water through any gap.

Cavity Drain Membranes: Waterproofing membranes, such as PermaSEAL cavity drain membranes, are used to coat the walls, floors, and occasionally the ceiling of your basement. They’re intended to create a gap between the waterproof membrane and the damp wall. The space created by cavity drainage membranes allows any water to flow freely. To a sump and pump, which then evacuates the water to an external drain, this liquid is directed via drainage channels. Because of the critical role played by pumps in this system, it’s essential to think about pump maintenance and even the installation of a battery backup system should the electrics go down. Internal (dry side) waterproofing membrane internal finishes are formed on the inside (dry side), therefore interior finishes are fully separated from dampness and stay dry.

BS8102 is a series of standards that regulate the building and installation of waterproofing systems in basements. The BS8102 Guidelines are a set of rules that govern waterproofing basement construction and installation. We also have an in-depth guide on how to install sump pumps and a comprehensive sump pump installation guide. Check out our 100 per cent recycled basement floor and wall cavity drain membrane, which is covered by the BS8102 Guidelines.

Who should carry out the Basement Waterproofing?

When it comes to basement waterproofing and basement conversions, you should opt for a professional business or individual to do the work. They will be able to suggest the best solution for your specific requirements.

When choosing a basement contractor, look for one that is a member of the British Structural Waterproofing Association or the Property Care Association.

Basement Waterproofing and Selling Your Home

The fact is that properties with waterproof basements are typically more valuable than comparable properties with damp basements. Even more so in high-value areas such as cities, a well-lit, friendly, and waterproof basement living area will add value. Buyers are frequently deterred by the additional cost and labour involved, but it’s a simple and quick procedure. A basement’s extra habitable space is a big selling feature.

If water is seeping into your basement, it’s an enormous problem. Mould growth will only get worse if it isn’t removed promptly. In a soggy basement, serious concerns like dry rot may develop and cause expensive structural damage as well as deter potential purchasers. A waterproof basement prevents these problems from occurring.

Basement Flooring

If you have an uneven floor, there are several options for flooring. Screeds, a concrete layer, and/or on top of the basement floor slab may be added. Screeds will take finishes and give you a lot more options for flooring; nevertheless, they do raise the height of the floor by 1 to 3 inches (2-8 cm). A floating hardwood or laminate plank is another alternative. These are generally built using tongue-and-groove boards with a waterproof membrane and/or insulation beneath them. When it comes to choosing your carpeting, remember that underfloor heating can be beneficial as well.

Insulating a basement

An air-conditioned basement keeps your house cooler in the summer and warms it up faster in the winter, saving you money on heating bills and providing a pleasant moisture-free living area. In this part of the chapter, we’ll be concentrating on basement interior insulation because exterior insulation is only used during the construction of a new basement and isn’t practical with an existing home. You should concentrate primarily on the walls rather than the ceiling when improving your insulated basements energy efficiency.

However, there are a few things to consider before making a decision. To avoid excessive humidity and mould formation, you’ll need some form of vapour control. Warm humid air must not reach the chilly basement wall and condense. A vapour control layer (vcl) should always be placed on the warm side of the insulation to prevent water vapour from the basement rooms from condensing on the cold cavity drainage system. It’s critical to install a functioning basement waterproofing system because any water entry may cause the insulation to become wet.

Ventilating a Basement

It’s crucial to provide adequate ventilation in your basement to make it a pleasant living area. Stale, musty air should be eliminated, and fresh air should be brought in. It is also critical for lowering humidity levels. Windows (if you have them) may be utilized to effectively ventilate a basement; open stairways, extractor fans, ventilation equipment, fans and vents are other methods.

Heating a Basement

To create a warm atmosphere in your basement, you’ll need some sort of basement heating. When it comes to heating your basement, there are several choices. The options and your budget will decide which ones are feasible.

Lighting Your Basement

If you want adequate light without taking up space, avoid pendant/hanging ceiling lights and stick to fixtures that give enough illumination. With this in mind, spotlights (check for harshness), track lighting (great for attaching to exposed ceiling beams) and wall lighting/wall sconces alternatives may be suitable. If you have a limited ceiling, recessed tiny spotlights are an option.

It’s always a good idea to use natural light in basements because it makes the area more welcoming and is more healthy. If you already have windows, make the most of them – get rid of anything that might be obstructing light from coming in. If you don’t have a window, consider adding one, increasing the size of an existing one, or adding a lightwell. Unless you’re restumping something that was previously allowed (such as rebuilt), this will almost definitely need planning permission.

You have a few alternatives if you’re looking to add some light to your basement. If you use a glass door on the entrance to the basement to let light in from above, you might want to think about more creative and pricey options like mirror shafts and light pipes.

How much does a Basement Conversion Cost? 

When it comes to budgeting for a basement conversion, you must first determine which chores can be completed by a do-it-yourself and which need the assistance of a professional. Some people will want the entire conversion to be done by a professional firm, but this will result in greater expenses. ‘How much will it cost to transform my basement?’ is one of the most typical questions we get. This is almost impossible to answer, but we can give you some ideas. If you’re looking for a quote, why not contact DBI?