Mmh...it's terribly hard to give you an assessment here. You are grabbing most things off the top shelf. Brickwork, photovoltaics + storage, KNX, light well, dormers, etc. You leave out nothing that drives costs. Then some things are still missing from your list or are explained too vaguely. 150 sqm with 1.5 stories including an office in the basement sounds hard to imagine. The upper floor would have to be very small. From experience, if you go for many top-shelf items, you follow through. Meaning you probably won’t have standard vinyl flooring or 30x30 tiles installed. At the same time, you budget 20k for the kitchen and incidental costs. Somehow, none of this adds up. What data are the 2,700 EUR from the architect based on? Past projects? Just an estimate? I would calculate. 150 sqm * 3,000 450k Basement partially livable (white tank?) at least 100k Garage 25k KNX (beware with "very good" it can quickly be more) 50k Photovoltaics with storage 25k Außenanlagen 25k (and that’s rather the minimum for paving/terrace/splash guard strip some hedge) Kitchen 20k Incidental construction costs 50k (there’s a separate thread here, construction water, construction electricity, earthworks etc.) Climate control, special wishes, buffer, brickwork, black box 50k Furniture, lighting, pleated blinds, odds and ends 10k Edit: architect etc. had slipped my mind 70k probably for this size You can still add more. This is rather good, normal standard (except for the extra listed items, of course). Außenanlagen can also quickly cost double.