Extension costs

[monkeyblonde]

We are at the stage in our home where we must extend or move. We bought the house 10 years ago with a view to making it our dream forever home - at that time we have very young children, time has passed and since Covid we have literally no idea how much an extension would cost. We are also on the cusp of paying off our mortgage so reluctant to jump back into a huge debt. Considering moving instead but again comes with additional costs.

It would require a ground floor remodel and a side single storey extension on top of the garage which currently has a flat roof.

Also having to weigh up living through this with two teenage sons. What would you do? We are hating living like this more and more each day.

Are you in London or the south East? How many square meters would you be adding? Do you know if the garage foundations are good enough for a second storey extension?

We are in the South East - Bucks.

We did have a builder round when we first moved in who confirmed that the garage could take a single storey 🤞🏻

Sorry - probably around 30 sq m

Move.

A rough starting point: a single storey side extension over an existing garage with ground floor remodel will likely cost £60-100k+ depending on your area, specification and how much internal reconfiguration is involved. Building over an existing garage can simplify foundations, but the flat roof structure may need upgrading to take the new load, which adds cost.
Before deciding, do the honest maths on both options. Moving costs (stamp duty, agents, solicitors, removals) on a property you've owned ten years could easily run £20-40k depending on what you're buying. But you end up with exactly what you want from day one, no dust, no builders, no six months of chaos with two teenagers.
The fact you're nearly mortgage-free is actually a strong position for either route. But don't jump back into major debt for an extension that might add only 50-60% of its cost to your property value.
Get a proper quote for the extension and a realistic figure for moving. Compare them side by side. The answer usually becomes obvious once the numbers are on paper.

Agree with @Abre, do the numbers in both options. I would allow £100k all in as there are bound to be additional things you will want to upgrade /furnish along the way.

The only thing I would add is that doing an extension you can get exactly what YOU want from the space rather than moving to someone else’s dream layout. May not be relevant if you find a great property though.

we have just done similar and the upheaval wasn’t too bad with teenagers vs last time when they were small kids! Moving likely to be much more stressful. Also figured the extra cost was worth it to get space how we wanted it and we use the whole house much better now. Good luck!