GARAGE CONVERSION AUDIT
STRUCTURAL LOFT CONVERSION AUDIT
PRE-PURCHASE FEASABILITY CONSULTATION
STEEL WORK CONNECTIONS
INTERIOR MINOR ALTERATIONS
CDM & ASSOCIATED REPORTS
HEALTH & SAFETY REPORTS
3D MODELLING (from)
SOIL INVESTIGATION REPORTS
AIR PRESSURE TESTING
BUILDING CONTROL APPLICATIONS
AIR TIGHTNESS TESTING
SOUND INSULATION TESTING
PART F VENTILATION TESTING
RENEWABLE ENERGY ADVICE & INSTALL
THERMOGRAPHIC SURVEYS & TESTING
CODE FOR SUSTAINABLE HOMES
PART G WATER CALCS
DOMESTIC EPC’S FOR LANDLORDS & HOMEOWNERS
Adding a single-storey extension will enhance the appearance of your valuable living space and should increase its financial value, and we will tell you how.
A single-storey extension is a cost-effective solution that allows you to design extra living space with a layout that fits the way your family uses your home. With glazing rooms, it can also give you the ability to create a light space that is integrally connected to the garden. So the benefits of a single-storey extension are numerous; just some of our suggestions are to use this room to: increase your capital, more room, guest room, room for rent, storage, children's playroom, gym, home office...
What is the cost of a single-storey extension?
Adding a one-storey house will allow you to transform the lower part of your home to better suit your lifestyle. But what should your budget be for that endeavour? Our guidelines will help you get the right planning and budget for your extension.
As with any other work, before you start planning your extension design, you need to set your budget and ensure that you can afford what you plan.
Start with construction costs that can be broken down as follows:
• Building work costs around £ 1,500 to £ 1,900 / m² (a 4m x 5m extension would reach around £ 30,000). For good quality, expect to pay between £ 1,900 and £ 2,200 / m². You will pay between £ 2,200 and £ 2,400 / m² for a high-spec extension.
When calculating costs, you will need to consider the professional project fee costs:
• Architect’s fees: around 3-7% of construction costs, with planning drawings around £ 2700, and construction drawings similar rate.
• Structural Engineer: For roof rails and foundations, you will need a structural engineer. It would cost from £ 500 to £ 1000.
• Survey: between £ 500 and £ 1500 if research on an existing home is required.
• Project Management: 3-7% of the construction cost for project management (you can arrange a daily or hourly rate). You can save money here if you can manage the project yourself.
• VAT: 20% of labour, materials and services
• Planning Fees: For a single storey residential allowance in England, the application fee is £ 206. If you need a certificate of legal development, you will pay £ 103 and cost £ 34 per the requirement to meet planning requirements.
• Building Control Fees: depending on the size of your extension, plan for between £ 200 (for an extension of 10m²) to £ 900 (for 80 to 100m²).
• Party Wall Agreement: This typically costs from £ 700 to £ 1,000 per neighbour.
• Extra fees: These can include a tree report (from £ 250 upwards), flood risk assessment in floodplains (from £ 250 upwards), an ecology report, as needed from your local authority (from £ 400), an archeological report if your home is in an archaeological site, historical construction report, probably if your home is listed. Do not forget the cost of interior design.
The cost to furnish the interior of a single-storey extension largely depends on the type of room you are adding, but expect to pay approximately:
• Between £ 5,000 and £ 30,000 for a new kitchen, depending on specification (larger kitchens can cost significantly more).
• The bathroom will cost from around £ 4,500 to £ 11,000, depending on the quality of the equipment; a shower will cost a similar amount.
• For floors, the budget is £ 25 to £ 100 per square foot.
• For wall and ceiling linings not covered by construction costs, set aside about £ 85 per square foot for plaster or dry lining, plus paint.
• Expect to spend between £ 1500 and £ 2000 per linear meter for double or sliding doors. These are a great way to bring in light and connect your home to the garden - and also create the feeling of even more space.
• Remember to include the cost of adding heating to your new room. Costs for underfloor heating vary: electric underfloor heating is less expensive to install, but more expensive to use than water supply (and some elements can be installed on a do-it-yourself basis). However, underfloor heating, although more expensive to install and may require the addition of a new boiler to meet demand, is less expensive to operate in the long run. Expect to pay around £ 2,500 for a new boiler. Expanding an existing single-storey central heating system can mean no more than two to three days of plumber work, about £ 150 a day without materials.
• For utility rooms, keep in mind from about £ 1,500 to £ 11,000, according to your size and level of shackles.
This will bring you a minimum cost of £ 45,000 for a single-storey extension of basic quality for 4m x 5m, including most fees but excluding the interior design costs that depend on you.
Planning a single-storey extension
Planning restrictions (such as how much your house is already expanded) will limit the size of your extension, but keep in mind that the larger the extension, the more cost-effective it is. As much as you have in mind selling a home sometime in the future, keep in mind that reducing the garden at the expense of your extension can deter potential buyers. Also, if you expand within the allowed development criteria you can build without going through the planning process.
From checking whether you need planning permission or expandable development permits, to finding the best construction team, good planning will be key to getting your extension completed on time and to your liking.
As far as planning permission is concerned, you will need it if you are planning a more ambitious addition. Planning restrictions will limit the space and height of your extension, but keep in mind that the larger the extension, the more cost-effective is per square foot.
You may still be able to use Development Permissions (PDs) for your extension, which allows you to build without the need for a planning request. The general PD criteria are described in detail on the Government's official website, so it's a good idea to check it out, but check with local authorities as well, as some areas have limited rights (such as conservation areas).
Designing a single-storey extension
The design of a single-storey extension, especially the choice of its style and material, may also be the most important decision you will make when building. It is the design that will dictate, in addition to the layout, how long it will take to build and how much it will cost. And by no means forget that the design of your extension can even increase or decrease the financial value of your property! With an architect, or with a builder and yourself only, these are things to consider:
The appearance of the interior
An open-plan, a series of smaller spaces, or a combination of the two? Think carefully about your needs before you start decorating your interior. Open plan, a series of smaller spaces or a combination of the two? Every decision is yours!
Doors and windows
Setting up windows and doors is key when you want to achieve a stunning effect. This is because the position, size, and shape of doors and windows that best bring in daylight and garden views can play a key role in this. Ensure that their style and frame match the style of the entire interior and the furniture in it.
Bringing the Outside in
By combining indoor and outdoor spaces, you will make both spaces feel larger and more cohesive. Think of the wide double folding doors overlooking the courtyard, the continuous floors inside, the treatment of the walls with plants, and you will create a unique space that extends from the house into the garden.