Renovation of an old building from 1969

sorry, as I read it, the costs of an energy consultation don’t matter to you, because even someone who immediately talks about triple glazing is not exactly a highlight but still better than the "experts" you are gathering.
And yes, if this is a chamber colleague, regardless of whether from the engineering or architects chamber, then they are liable for this statement, because this is already advice, even if the statement was made free of charge and without contract.

7cm AW insulation is better than nothing, but still somewhere a half renovation if you already tackle the trade. The window area will possibly only make up a small part of the AW. The required U-values can be found in the BAFA subsidy program.
For the renovation of the top floor ceiling, the vapor barrier is important if the ceilings are not plastered from the inside.

80% underfloor heating already requires 2 heating circuits, the 12.5cm already influences the supply temperature and is quickly insufficient in rooms like a bathroom or dining room. Fortunately, the room heat load calculation has now become mandatory. Although it is still overridden by the building heat load, even though the thermal protection certificate has nothing to do with it at all.
Condensing technology is almost equivalent compared to the heat pump; both are a tragedy, max. 50% of the lifespan of the old heating technology. But politically caused, you have to reckon with longer runtimes in LCA/LCC. Or in other words, if something runs for 15 years... but I have never had this with any of my builders.
It is comparable to the downsizing of combustion engines.

There is no airtightness in construction; it does not achieve even a passive house. Even if the static proof of the Sd value of a component joint fails, dynamic proofs show that even gross nonsense by the window fitter is possibly still provable without damage. Here, the decisive factor is the Uwf value in relation to the U-value of the reveal and still the glass pane is the coldest surface component.

Here it really shows how fatal it is to pause the funding for iSFP/energy consulting.

My plans are:
All new (triple glazed) or rather double glazed?
Insulate the facade with blown-in insulation.
The roof ceiling is made of concrete and I would like to insulate it from above. Probably with stone wool. Or alternatives?
Insulate the basement ceiling with 10 cm polystyrene.
Underfloor heating will be installed in 80 percent of the house and milled into the screed.

Sounds basically not wrong at first, more later...

An energy consultant is no longer subsidized. Is this necessary if I don’t get any building subsidies anyway?

Yes, in BEG individual measures and KfW efficiency house (261, loan with repayment subsidy) it is subsidized with 50% of the costs. At the moment, the funds are only frozen. - Only the e-car premium was stopped overnight.
The energy consultant does more than just make the list you wrote above. He creates planning details for thermal bridges (window installation, transitions from ceiling to wall, floor to base, etc.), which is especially useful with a combination of external insulation (roof from above, basement from below, and blown-in insulation). Some colleagues also create room-by-room heat load calculations. If the efficiency house renovation is done anyway and the room-by-room heat load is to be determined from the start, that is little additional effort. As part of construction supervision, he checks the execution for implementation as ordered and, if necessary, defects and faults.
He also advises on insulating materials, number of glazing layers in windows, and creates an airtightness concept if needed, and checks summer heat protection.
Depending on the original profession of the consultant, he can also help with heating matters, e.g., design of underfloor heating and heating circuits.
Much is possible without a consultant; some things can go wrong.

Two craftsmen told me I should rather take double glazing instead of triple glazing because of mold. But I think there is a lot of myth involved. An energy consultant (not engaged) told me to take triple glazing.

As said, some things can go wrong. Both craftsmen have no idea about the “new windows in old buildings” topic and the consultant should not make such general statements. Spoiler: The basic problem is the same with both glazings.

My cousin is responsible. He is a plumber. His statement was: Leave the as it is.
It will easily run for another 20 years. In that time heat pumps will become cheaper or might not exist anymore. (He’s not a big fan of them because he thinks that heat pumps break from time to time and need to be replaced, which is always quite expensive for the customer)

Whoever believes that heat pumps will not exist in 20 years also said in 1994 that the internet is a passing trend.
Immediate replacement is certainly not necessary, but for a KfW efficiency house it is necessary. Subsidies in 2024 (if they can be financed) will also be generous as planned, about 60% for an air-water heat pump with R290 (propane). For step-by-step renovation or without an efficiency house, I would also initially keep it – but design the heating circuits for low temperature and, above all, hydraulically balance them properly.

7cm external wall is better than nothing, still somewhat half renovation if you’re already doing the trade.

Cost/benefit is that blown-in insulation is simply top, and the additional savings from extra external wall insulation will never recoup the money. Especially since the existing clinker facade is maintenance-free, unlike ETICS with plaster. - Only if KfW55 is to be achieved, it might be necessary.

For renovating the top floor ceiling, the vapor barrier is important if the ceilings are not plastered from inside.

It is a concrete ceiling = integrated vapor barrier. Airtightness is important.

Whether with BEG individual measures, KfW efficiency house, or largely without subsidies: if you have no idea, about 1000€ (minus 50% subsidy – or more in 2024) are well invested for a consultation with ISFP, help with questions about implementation details, and heat load calculation for the finished renovated house.

With 7cm of blown-in insulation, you won’t even meet the requirements of a KfW monument (160% Energy Saving Ordinance 2002), ... just because you mention a KfW55.
Airtightness:
The equivalent leakage area for the construction year corresponds to a permanently open window up to 70 x 70 cm.
For comparison, in a new passive house with about 400m³ volume, it is still the size of a cat flap.

Utilizing 60% or even 70% of the investment in a heat pump only makes sense if you later achieve a corresponding annual performance factor in operation.
This would have to be between 3.6 and 3.8 at current prices. Current studies show values around 2.2; even Fraunhofer had to backtrack when considering the "factor" of the actual workmanship by contractors.
A CO² saving is only possible from an annual performance factor of about 2.6.
The hydraulic system is precisely the problem here. And how practice looks regarding the completed VdZ form, often without a room heat load calculation, because one simply follows the thermal insulation certificate, which says nothing about this... the heat pump is chosen too large and the cycling can never work out...
Besides the fact that the heat load for the heat pump according to VDI should be calculated dynamically...

First, you have to find a planning office that can do this and wants to do it.

And the heating lobby is currently upset in Berlin because supposedly the hydraulic water-based heating system is the competence of German heating engineers,
probably more because many DIYers are now switching to air-based systems or using them to support their peak heat producers.

With 7 cm blow-in insulation you will not even achieve a KfW monument (160% Energy Saving Ordinance 2002),

KfW monument only requires the minimum thermal protection according to DIN4018 for the maximum U-values. KfW monument is therefore not dependent on the facade - and with 7 cm WLG 035 as blow-in insulation it is very well achievable. Since the questioner does not have a listed building, I do not even know how you come to that conclusion - it is irrelevant here. I wrote that the ETICS in addition to the blow-in insulation is only necessary if a KfW Efficiency House, e.g. 55, is targeted. It will probably already be necessary for KfW85. But if you do it anyway, you might as well go for 55.

Otherwise, I do not understand what I am supposed to do with the fact that an old building is leaky or many plumbers cannot properly install or plan heat pumps? I only said that many things can go wrong and that an energy consultant is useful in this case (extensive renovation, new heating planning, possibly subsidies, owners without expertise). I also did not advise the questioner to install a heat pump, but only that it would be necessary for the KfW Efficiency House matter.

@dertill
I am only making comparisons to your comments because everyone, when they hear the word airtightness, thinks it also means achieving an airtight house at the same time.
Just as poor a 7 cm insulation is in comparison, I therefore mention the KfW standards and how far 7 cm is from them.
I have a 90s house and still miss a KfW55 with 25 cm ETICS.

@dertill I am only making comparisons to your comments because everyone thinks that the word airtightness also means achieving an airtight house at the same time. Just like how poor a 7 cm insulation is by comparison, I therefore mention the KfW standards and how far 7 cm are from that. I have a house from the 90s and still miss KfW55 with 25 cm ETICS.

The comparison is not wrong, but I believe very few imagine a balloon with windows when thinking of an airtight house.

I still have to disagree about the "poor" 7 cm insulation. 1. That you miss KfW 55 with 25 cm insulation is not due to the wall of the house but other areas. Your house would also miss KfW 55 with 100 cm WLG 022 on the wall. 2. Assuming a U-value of the existing double-shell wall of 1.5 W/m²K (according to DIN4108, 1970), adding 7 cm WLG 035 in the air layer results in a U-value of 0.4 W/m²K. Although this does not meet the requirements of KfW or BEG individual measures (0.2) or for a Building Energy Act new build (0.24), it reduces heat loss through the wall by two-thirds. The surface temperature rises from approx. 12.6 °C at NAT (DIN4108) to nearly 17.6 °C. With 16 cm WLG 035, you would get one degree more, but both are far from the critical range for dew formation and corresponding mold growth. Also, the outside of the existing clinker remains largely free of moss and algae growth due to the "poor" insulation, unlike the plaster on an additionally applied ETICS. Regarding costs, blown-in insulation is about €25/m² and already achieves 80% of the possible heat savings (up to U = 0.2 W/m²K). The additional 20% is only reached with another almost €200/m² for an ETICS. The "poor" insulation therefore has many advantages, especially if the builder also cares about the € in their wallet.

A specific heating energy demand of the building low enough to operate it with a surface heating system with a low flow temperature can also be achieved with blown-in insulation alone. This can then also be done temporarily with oil.

The only sticking point is ensuring the driving rain tightness of the existing façade. This can, if necessary, be achieved by repointing the weather side. In buildings from 1970, this is usually not necessary, and the assessment can be made during the energy consultation.