Top tips for planning an extension to your home

Based on my own experience of taking on 2 large home extensions I thought I would put a list together that might help someone avoid the mistakes that we made!

1. Money and budget

Before going ahead with planning permission or anything you need to make sure you have the finances to take on a project like this. If you need to re-mortgage your current property to afford this I would advise seeing your current mortgage lender. If you are not tied into your mortgage it would be sensible to have a look around at other options.

2. Timescales

However long your builder tells you it is going to take double it! Be prepared, unlike us, for it dragging on. We were told 12 weeks for one project that actually took just over 6 months!

For large projects you might want to consider agreeing late penalty fees if the project runs over.

3. Planning

Before getting any quotes you may need to get planning permission. We used a local architect who took care of all of this for us. He drew up the plans for the extension based on the information we gave him. He also dealt with the local council for planning permission.


Once planning is approved your next step is to get quotes from local builders. I would always say go with a recommendation from someone who has similar standards to yourself. We actually used a local builder that had already smaller jobs for us and we were happy with.

We had also used other companies for services such as new windows and we regret not asking our builder to use the company we were happy with. We ended up with decent windows but not stunning ones like we were hoping for. Don’t be afraid to ask your builder. It would have cost us more money but we would have been happier with the results.

One of the projects that we did we tried using different tradesmen to save money instead of going to a larger builder who would use contractors. We had problems with each of them blaming one another so on our second project we went with the one builder and this worked much better.

5. Tell your neighbours

Just out of courtesy you should tell your neighbours your plans and let them know when the building work is going to start and how long you expect it to take. We were not prepared for the amount of noise and parking issues it caused.

6. Building Work

Once the building work gets underway I would recommend having regular meetings with your builder. We just left them to get on with it and after 2 months realised that they were way behind schedule.

7. Snagging

We quickly found out the earlier you start with a snagging list the better. Don’t leave it to the builder. They tend to wait until very near the end of the work. Once our second project was well on its way we gave our builder a weekly snagging list. It helped him to organise who he was sending to us and we feel that the work moved on quicker.

8. Quality of work

I have already mentioned the windows that we were slightly disappointed with but another area that wasn’t quite done to perfection and my wife is a perfectionist was the flooring. If you are having a new extension then you need to make sure that where the old floor meets the new floor is absolutely spot level. We had a lovely, expensive Karndean flooring laid all the way through from the dining room through the kitchen and into the utility room. However there is a slight bump where the floors meet. Ensure that if you are having flooring that crosses the border from the old building to the new that the flooring is perfect especially if you are laying something like Karndean or tiles.

9. Decorating

Once all the building work is completed the decorating can begin. I am not too bad at decorating but if you still have enough money left after paying the builders I would recommend going for a professional decorator as the finish will be much better than if you decorate yourself.

I am sure there are bits I have missed but I hope that these tips will help you to avoid the hiccups that we had. Good luck!