ᐅ A bit unsure about the heating system—it's a tough choice.

Erik_IEU schrieb:
....The keyword here is holistic and integrated planning, meaning nothing should be categorically excluded, and the architect is not the only one who should be involved in the planning process!

Correct. First of all, everything should be open.

Erik_IEU schrieb:
.... including an MEP planner, although many project leaders (architects) are still hesitant about this due to the supposedly “additional” costs for the client.

The costs are relatively low. Architects usually base their billing on the HOAI fee structure. In the single-family home sector, an MEP plan according to HOAI is not necessarily required. It is usually sufficient to focus on the critical key points (individual details). For a typical single-family house, the cost is approximately 1.1 to 1.6 thousand euros, depending on the agreed scope of services and the level of complexity. A full MEP plan, in my opinion unnecessary, costs three to four times as much without any significant benefit for the client. Additionally, with a focused plan it is much easier to find a suitable system installer who can contribute their own practical experience, which is not the case with a HOAI-based plan where almost every single screw and clamp is specified.

Those who do not want to invest in focused planning will have to accept a less economical system in the long run.

Erik_IEU schrieb:
....The energy consultant and/or MEP planner support the development of a long-term concept, which should start with everything open.

The most effective approach is the dual role of MEP planner and energy consultant.

Some technical universities have recognized this and now offer relevant degree courses, although this is still rare.

Historically low interest rates favor higher initial investments with lower subsequent consumption costs, while high interest rates tend to favor lower initial investment but higher ongoing consumption costs.

However, it is certain that the specific costs of all energy sources will progressively increase in the future; to what extent, nobody knows—not even the speculators who contribute to price inflation.

Energy will likely become a luxury good. Anyone who manages to implement a concept of energy independence in the annual balance—i.e., heating and hot water costs approaching zero—will be well off.

Best regards.

NB: Future energy costs for heating and hot water are already influenced by site selection, building orientation, as well as the construction and geometry of the building envelope!

€uro schrieb:
The costs for this are around €1,100 to €1,600 (approx. $1,200 to $1,750) for a "standard" single-family home, depending on the agreed scope of services and complexity. A complete HVAC (heating, ventilation, and air conditioning) design, which I consider unnecessary, costs three to four times as much without providing any significant additional benefit to the homeowner. Moreover, with a focused planning approach, it is much easier to find a suitable system installer, as they can bring in their own experience. This is not possible with a full HOAI (official fee structure for architects and engineers) design, where virtually every screw and clamp is specified.

Those who cannot afford focused planning will have to live with a less economical system in the long run.

Do you include your own costs in the economic calculations?

With an additional €1,600 (approx. $1,750) in fees to be financed, the homeowner could instead afford to use 10€ (approx. $11) more gas every month for 20 years, without any other heating system performing better.

Now, the argument will probably be made that energy prices will rise, so in the future much less gas can be bought for the same 10€. I am well aware of that.

But how do you explain this worst-case scenario to the homeowner—if, at the end of your calculations, it turns out that the standard heating system proposed by the general contractor, gas plus a solar thermal system, is the most effective option for their single-family home and they have wasted the €1,600?

A valid question...

Musketier schrieb:
Do you also include your own costs in the economic calculations?

Of course, otherwise it would hardly make economic sense for the client ;-)

Musketier schrieb:

With an additional €1600 in fees to be financed, the client could instead consume 10€ more gas each month for 20 years, without any other heating method being better for you.

Hard to believe, where does this knowledge come from? ;-)

Musketier schrieb:
...Now the argument will surely be made that energy costs are rising and therefore much less gas will be available for the 10€ in the future. I am well aware of this.

Regarding speculation about future energy prices, I prefer to leave the decision to the client, who can influence this as they wish (interactive consultation, planning). I naturally advise according to my knowledge and experience.

Musketier schrieb:
...But how do you explain the worst-case scenario to the client—if in the end your calculations show that the standard heating system proposed by the general contractor, gas plus solar thermal system, is the most effective solution for their single-family home and they have wasted the 1,600€?

That is 99.9% unlikely, mainly because solar thermal systems are far from economical in single-family homes ;-) Regardless, anyone who thinks that with, for example, a gas condensing boiler, exact planning is unnecessary for whatever reason should take a look at poorly executed real-life systems.
Also, take a look at the contract documents from a general contractor! Is there any contractual guarantee regarding expected energy costs? Hardly :-) At best, the required efficiency level to be achieved on paper is stated, but nothing more. Unfortunately, the vast majority of general contractor projects fail to reach this level in practice, mainly due to inadequate planning! And then—lawsuits with high effort and uncertain outcomes, even though the building budget is fully or excessively used?
This can be avoided in advance.

Best regards