We actually already have everything included in terms of major items we wished for, electric roller shutters complete (€11,000), central ventilation system (recoVAIR) (€12,000), and chimney (€6,000) and are still quite a bit under the specified price (currently €249,000 house price). The base price for the bungalow in our region is €209k. Any floor plan changes are included for us at no extra cost. The surcharge for the interior walls at 17.5cm, which is now required by them, is around €10,000. For everything else, we still have a generous buffer. Incidental construction costs etc. are of course separate again. We estimate about €2100-2200/m². What is added for sockets and tiles we can clarify directly with the trades on site without Town & Country involvement, so the additional costs there are still somewhat limited. I am still undecided between gas and LWWP but despite rising gas prices, I still feel better off there. Electricity is not getting cheaper either and the outdoor unit is still a thorn in my side. Geothermal is unfortunately too costly in terms of initial investment.