ᐅ Is a solid (masonry) house significantly less energy efficient than a timber-framed house?

Hello everyone,

My wife and I had a meeting yesterday evening with a construction manager who is connected to us through several acquaintances. It turned out he works for Keitel-Haus. He strongly advised us against building a solid construction house (concrete or masonry), giving arguments such as:

• Solid construction houses have a much higher heating energy demand, costing around €2500 per year with a heat pump compared to €800 for a timber house
• The moisture from construction remains inside the building even after completion, leading to an unhealthy indoor climate
• Masonry walls have not changed significantly since the 2009 energy-saving regulations, and some figures are manipulated to meet current thermal insulation requirements
• For solid construction houses, the primary energy demand is never calculated properly; you essentially buy the heating system blindly without coordination with the building

As a trained civil engineering technician with a strong background in concrete, I was naturally shocked by such allegations.

Does anyone have experience comparing these building methods? I only found one online study indicating that heating costs for solid construction are actually lower than for timber houses.
We want to build the house with a regional provider, who are mostly solid construction builders in our area... and so far, we have had the best feeling regarding their advice and service. Google also shows no negative reviews.