Hi, we have a French holiday home but our main home is in the UK. If we were to sell our French house to buy another French one would we still have to pay capital gains. Or can this be carried over to the new more expensive one. We have owned the current on almost five years but carried out all the renovations ourselves. As I understand it we cannot claim for these expenses of a fair amount of tax may be due?
Yes CG will need to be paid, I think the gain needs to be declared to both the French and English revenue and I believe you are correct that you won’t get the value of any DIY improvements taken into consideration. As always if not sure seek professional advice.
Hi Anthony… I think…this link might help you… although it is dated 2015… 
From what I have read on the link… as a UK Resident, you would be liable to 19% CG tax + 15.5% Social charges (or whatever it is called)…on your French holiday home… speak with a Notaire for full details, including whatever Allowances you might benefit from…
A 5% Rebate clocks in after the 6th year of Ownership (?)… so might be worth hanging on a bit…
https://droit-finances.commentcamarche.com/contents/9887-plus-values-immobilieres-des-non-residents
No idea what the UK will demand from you… 
Here is a link to explain how it works in France, helpfully it’s in English and extremely thorough.
You will also need to report the gain in the UK. If you normally complete a self-assessment tax return then you need to include it on that. You can claim for the costs of purchase and costs of sale (solicitos/notaires fees, agents fees etc) as well as any improvements such as an extension. Because of the double tax agreement with France you will get a credit for the tax already paid in France against any tax due in the UK.
I strongly suggest that you get professional help particularly if your gain is likely to be significant.
Best of luck!
You can adjust factor in certain costs of improvements works, done by french businesses/artisans who have a siret or siren number and where you have a receipted bill.
“du montant des travaux que vous avez réalisés sur le bien, à condition de pouvoir en justifier par la production de factures émanant d’entreprises”
This looks interesting as well. The French government website, also very helpfully translated into English.
Of course, Anthony has clearly said that he has done all the improvements himself… … so, without Artisans’ Bills… I don’t think it will be deductible… but, as I have already said… the Notaire “knows all”… and will advise…
I missed that sentence! Mind you, anyone who is getting any capital gain at all these days is in a pretty good place…