A home extension is a fantastic way to get the extra space you need in your home and also add value. Perhaps you have decided a home extension is right for you.
What is next? How do you build a home extension? Where do you start? What happens throughout the process from start to finish? Our helpful guide will show you how to build a home extension.
1. Hire an Architect.
An architect will help you design your home extension, they will advise what will work for your property and be the experts to guide you and produce a full set of drawings. Hopefully, they will also help you apply for planning permission if it’s required Home Extension Guide Part 2 – Planning Permission
2. Structural Engineer
This can be arranged with your architect, but they will need to work with a structural engineer to ensure the extension is built to building regulations. Even if you do not need planning permission for your home extension you will need to comply with building regulations so structural calculations are important. See our article ‘What Are Structural Calculations? Will You Need Them?’
3. Party wall Surveyor
If you notify your neighbour about the works and they do not give you written permission to go ahead then you enter a party wall dispute and will need to appoint a party wall surveyor. Read our article ‘What is a Party Wall Surveyor? And Do I need One?’
4. Select a Builder
It’s time to select a builder at this stage to carry out the works. We advise getting quotes from at least three builders on a like for like basis for comparison. Check reviews, ask to see examples of their work too.
5. Now you know what type of extension you are adding to your home, if planning permission was required and in place, you have chosen your builder and your drawings are complete. You are ready to start the build of your home extension. Building control are to be informed.
6. Time for the Builders to Prepare On Site
You may decide to hire a Portaloo rather than have the builders use your bathroom. They will bring their tools and equipment, clear the site, perhaps put up fencing and some materials will be ordered. Make sure your builders have given you a schedule of works or a timeline that they are working to so you have a clear idea of what plan they are following and you will know if they are running behind or on schedule.
7. Ordering Windows and Doors
There can be a long lead time on certain windows and doors so it’s beneficial to decide which type of windows and doors work for you at an early stage. Discuss this with your builder and find out the lead times to ensure they are ordered on time and do not hold up your project. Watch our video for ideas on windows and doors in your home extension. Watch this video
8. Dig Foundations
Based on the measurements on the approved drawings, it’s time to dig the foundations. The area will be marked out where the foundations are to be dug and then either by machinery or by hand the foundations will be dug to the correct specification. Building control will need to approve this.
9. Drainage, Manholes and Concrete Foundations
Next stage the concrete is to be poured into the foundations that have been dug and levelled out. This will also be where any drainage is put in, manholes moved etc. Building control will want to check this.
10. Brickwork to DPC
Once the concrete is set and dried to the right level its time to start on the brickwork. DPC stands for damp proof course height which is normally above 150ml above ground level. You will also create the damp proof membrane on the floor of the extension.
11. Brickwork to Roof Height
The next stage will be to extend the brickwork up to roof height.
12. Roof Structure Complete
The next stage is to build the roof. On an extension people normally choose between a flat roof and a pitch roof. If there are skylights going in then the builders would normally leave an opening for this.
13. Roof Complete and Watertight
This is where the roof is fully tiled and made watertight. Skylights or rooflights will be inserted.
14. Knock through
If there are structural posts or steels this is the time to knock through into the existing building. Building control will want to check the structural works including brickwork, roof, timbers and steels.
15. Internal Works
First fix plumbing and electrics and windows installed. The lights positions will start going into place with sockets and radiator positions.
16. Insulation and plasterboard
This is where the extension will be insulated to become thermally efficient and then the entire room would be plaster boarded ready to skim. A building inspector will check the insulation.
17. Plastering Complete
Skimming is done and the room is plastered.
18. Kitchen Installation
Now for when the room really takes shape, it’s time for the kitchen installation. Read our article on Kitchen Design
19. Second fix Plumbing, Electrics and Carpentry
Light switches and sockets to be added, skirting boards, architraves, doors.
Time for your swanky new floor to go down (this can happen at the same time as step 19 it just needs to be coordinated well) Read our article on Flooring
This is where all the little bits that have been missed or need to be finalised should take place.
Once snagging is complete you will have reached completion. Now final bills should be settled (unless you have a retention in place) all certificates and manuals should be received from the tradesman and the building inspector is to give the final once over and issue a certificate of completion. And now you have a shiny new extension to enjoy!
Watch our video that discusses the process of a home extension
There are many aspects involved in building a home extension and lots of different skill sets required. Hiring a design and build company like Jeffery & Wilkes who will handle the whole process from the start to finish can really take the stress away from the project.
If you would like to discuss plans to extend your home call Jeffery & Wilkes today on 020 88193883 to arrange a FREE, non-obligatory quotation from one of our experts who will advise how you can add maximum value to your home.
Download our FREE guide here to creating a home extension with the WOW factor