Basement Conversion

A basement conversion can be an extremely good investment. It creates fantastic useable space within your home for a variety of purposes. We can provide the necessary design drawings for your conversion.

Converting a basement can transform a cold, damp dirty space into one of the best rooms in the house. Used for a wide variety of purposes, it increases the habitable floorspace of your property thereby raising its value.

Real Homes have a number of useful articles about Basement Conversion projects

Design Parameters for Garage Conversions

Basement Conversion – The simplest basement conversions improve a space which already has ample head height. The most difficult involve digging down and underpinning the existing building. They can involve extending out under the garden, adding pools and cinema rooms. Other clients convert the basement into a self-contained flat.

If the building is constructed from solid walls (before cavity walls were adopted), any water in the ground outside will find its way inside. Basements are usually retaining earth and moisture the other side. Tanking must deal with any water coming through. Some mid-terrace basements are relatively dry. These usually have a neighbour’s basement the other side of the party walls.

We can develop basements into habitable rooms fit for families.

Have a look at some options from Google Images

Planning & Permitted Development

Basement conversions generally do not impact upon the external appearance of the building. They can often be completed without having contacted the planning office, however some Clients hope to rent out the basement as a separate entity. The planners will need to pass judgement on this. There are a number of other factors related to planning and permitted development.

Visit our Planning page

Click for information about Planning for Basement Conversions on the Planning Portal

Party Wall Notice

If you are building within 3m of your neighbour’s property and /or your excavations are deeper than theirs, or if you are within 6m away and your excavations are deeper than a 45 degree angle downwards from theirs, the party wall act applies and a Party Wall Surveyor will need to issue a party wall notice to your neighbour. This informs the neighbour of your project and how it will impact upon them. The neighbour can agree to the contents of the notice. If they do not agree within the timeframe, a party wall award is developed, which states that both parties agree to the changes. Both parties must sign the award before development begins.

Click for Party Wall information

Basement Floor & Wall Tanking

The level of tanking and system needed will be determined by how much water is coming in. Common methods are injecting the walls or using egg-crate systems with sumps. A plastic membrane on the walls and floors, along with insulation, ventilation and heating can improve a basement immeasurably. Tanking is a specialist area and we recommend you consult a professional to recommend the best course of action for your particular basement at a cost which suits you.

New Basement Floor

Basements for habitable use need a thick layer of insulation and new floor finishes. These things reduce the head-height in the basement, making the ceiling too low. Therefore, it is often necessary to break up the old floor slab and start again to achieve modern standards.

This involves digging out earth before laying any drainage for new bathrooms and kitchens. Damp proof membranes are used to keep water out, with layers of insulation, concrete and screed. Underfloor heating can be added if required, before laying the final floor finishes.

Basement Conversion – Technical Design

The technical design must detail the following:

• Structural alterations
• Improving access from the house above – stairs – decorate entire transition to upstairs
• Improve access from outside – stairs – handrails / paving / surfaces / drainage
• Alter the floor to add insulation, membrane(s) underfloor heating etc.
• Insulate, tank and line the walls
• Improve any windows and lightwells
• Move meters – develop a strategy for where these should go early on. Cupboards or secret spaces behind wood panelling work well.
• Install kitchen, bathroom, plumbing, heating and electrics
• Provide fire compartmentation (if creating a separate flat)
• Install or extend fire alarm
• Add finishes

We are familiar with the details needed to describe the above. We are able to develop a technical design package which will attract building regulations approval.

Visit our Technical page

Click for information about building regulations

Click for LABC information

Structural Design

The basement contains loadbearing walls so calculations, leading to a design, will be needed before any changes are made. A structural engineer usually provides this service. Also, if the slab is being lowered below the foundations the house will need underpinning. The engineer will consider the impacts upon the whole structure and design accordingly. We act as lead designers and send our architectural design to the engineer to work from. Once complete, we will co-ordinate his design with ours to create an integrated design for building regulations and construction.

Enquire about a Basement Conversion

Call the office on 0113 318 3078 or 07772 750 855, email enquire@we-draw-buildings.com or send a message via the contact page.