ePrivacy and GPDR Cookie Consent by Cookie Consent What's the best order to build your house extension: top down or ground up? | Resi

What's the best order to build your house extension: top down or ground up?

Top down or ground up, how should the works begin on your project? Find out more with our exclusive tips.

2 min read


We’ve recently purchased a semi-detached terrace house. We know that we’d like to add both a loft conversion and a ground floor extension, but what order should we build them in?


Since 2007, Resi architects have helped over 650 people to convert and extend their homes. In terms of the process, everyone has different priorities: some people want to complete all as quickly as possible, some want to phase the works, some want to live in their home throughout, or would prefer minimal disruption, or minimal cost.

Assuming that you want to complete your dual project as efficiently and effectively as possible, it’s usually best to begin from the top down. Even if you’re building both parts in one go, starting with the loft conversion makes the most sense for several reasons:

  • Erecting scaffolding over a garden or patio rather than a finished or in-process building project will be cheaper.

  • There is less chance of damage to the glass/finish of your completed kitchen extension.

  • Most of the time the contractor will be able to access the roof void from the front elevation without disrupting your lives, meaning you could continue to live through the project for the first 4-6 weeks relatively undisturbed.

Generally a loft conversion begins with the structural shell, which will be weatherproofed. Once this is done, the scaffolding can be removed and the structural team can move downstairs to begin work on your ground floor extension, while your contractor puts in stairs and finishes the interior of the loft.

If you are phasing the works so you can remain living in your home throughout, fully completing this stage first might even allow you to move into your finished loft while the ground floor is being worked on. Be aware that if any structural walls are being removed or replaced by beams, you cannot continue to live on the upper floors, and you may still have to deal with disruption as a heating system and electronics are added.

One thing you should never do is begin decorating the upper floors of your home while the ground floor extension is ongoing. If any walls are being removed, or the building needs to be propped in any way, there is likely to be damage and/or cosmetic cracking to the rooms above. Save putting in your luxury bathrooms until the very end.

If you have questions about your building project - or need affordable, high-quality architectural drawings - book a free consultation call today.

Design your own extension

With Resi Ready, you do the designs yourself on our whizz bang tech configurator. It’s the simplest way to get a spiffy new home extension.

Let's have a play

Related articles

Resi is the UK's largest residential architect


Track record in getting planning approval


Projects undertaken across the UK

28 days

Average time from survey to planning