ᐅ Renovation Issues for a 1972 Older Building

Hello, I want to renovate my house:
Built in 1972, with 24 cm (9.5 inches) calcium silicate bricks.
The plan is to add walkable insulation of 28 cm (11 inches) on the top floor ceiling.
External thermal insulation composite system (ETICS) with 16 cm (6.3 inches) polystyrene, basement ceiling 12 cm (4.7 inches), plus triple glazing.
Currently installed is a 2007 oil boiler Viessmann Vitola 222 connected to a stainless steel chimney, and a 5700-liter (1505 gallon) steel heating oil tank.
A dry system underfloor heating by Joco will be installed throughout the house.
Water pipes will be completely renewed using plastic.
No residual current device (RCD) protection switch. So, completely new electrical wiring as well.
Roof tiles are concrete. They will be sandblasted and coated.
Question:

I can get a pellet boiler ETA PU 15 for about 6200 euros including tax minus 2500 euros BAFA subsidy. Plus a layered storage tank of 825 liters (218 gallons).
Would you keep the oil boiler or switch to pellets?

Should a mechanical ventilation system be installed? What do you think about this? About 5000 euros.

blader schrieb:
...Would you keep the oil boiler, or switch to pellets?

At some point, the existing oil boiler will reach the end of its life. Usually at the most inconvenient time ;-).
With the energy efficiency improvements to the building envelope, the heating demand decreases. As a result, the old boiler would cycle far more frequently.

blader schrieb:
Should a mechanical ventilation system be installed, what do you think? About 5000 Euro.

A lot has already been discussed about this here => search function!

Best regards.

As a layperson:

If you wrap your house airtight in plastic, you quickly get stuffy air and condensation at weak points. To somewhat prevent mold and suffocation, frequent ventilation is necessary.

Alternatively, leave out the plastic and proceed in an economical/ecological way. That means using breathable materials and renovating naturally – but this seems to be completely out of fashion.

When calculating costs, please don’t forget the maintenance of the quickly moss-covered exterior façade...

blader schrieb:
Hello, I want to renovate my house:
Built in 1972, 24 cm (9.5 inches) sand-lime bricks.
The plan is to install walkable insulation with 28 cm (11 inches) thickness on the top floor ceiling.
External thermal insulation composite system (ETICS) with 16 cm (6.3 inches) polystyrene, basement ceiling insulation 12 cm (4.7 inches), plus triple glazing.
There is an oil boiler from 2007, Viessmann Vitola 222, connected to a stainless steel chimney, and a 5700-liter (1505 US gallons) steel oil tank.
A dry system underfloor heating by Joco will be installed throughout the whole house.
Water pipes will be completely renewed in plastic.
No RCD (residual current device) protection switch. So, the entire electrical wiring will be replaced.
Roof tiles are concrete. They will be blasted and coated.
Question:

I could get a pellet boiler ETA PU 15 for about 6200 euros including tax minus 2500 euros BAFA subsidy. Plus a layered storage tank of 825 liters (218 US gallons).
Would you keep the oil boiler or switch to pellets?

Should a mechanical ventilation system be installed, what do you think about that? Around 5000 euros.

Hello blader,

You can renovate like that, but you don’t have to. The house certainly has a good ecological balance now, which will rapidly worsen with all those chemical insulation materials, as will the indoor air quality.

I would not choose this approach for renovation and would avoid turning my building into hazardous waste!

Best regards

Karsten Brodbeck

blader schrieb:
No RCD (residual current device). So, a completely new electrical wiring as well.

Rather unlikely. It is much more likely that the RCD can simply be retrofitted.

blader schrieb:
Roof tiles made of concrete bricks. They are being sandblasted and coated.

What is the purpose of that?

Hello blader

§
EPS external insulation with 16cm (6.3 inches),

Although not asked, there are better exterior thermal insulation options today than vapor diffusion-tight, single-use waste insulation materials that release toxic fumes in case of fire. And why only 16cm (6.3 inches)?

blader schrieb:

Question:

I could get a pellet boiler ETA PU 15 for about 6200 euros including tax minus 2500 euros BAFA subsidy. Plus a stratified storage tank of 825 liters (218 gallons).
Would you keep the oil boiler or switch to pellets?

Is your budget still sufficient, or are you tight on financing? What are the costs for removing and disposing of the oil heating system including tanks, and what are the conversion costs to pellets? Do you want to have a pellet heating system later that requires regular care like an oil boiler (chimney cleaning, ordering pellets), or would you prefer a more maintenance-free system, such as a heat pump with ground source drilling?

blader schrieb:

Should a mechanical ventilation system be installed, what do you think about that? Around 5000 euros.

Definitely yes! If you seal your house and install airtight windows, mold growth is very likely without proper ventilation because warm air is trapped inside, and moisture cannot escape. Warm, moist air creates an ideal environment for mold. Achieving the necessary air exchange through window ventilation does not work well if you are employed, travel often, or don’t want to air out by fully opening windows every hour in winter and summer!

I am straightforward and honest; I hope I have not offended you. My intention is not to attack anyone personally but to provide food for thought!

Enjoy your 1970s house!

Kind regards

K.Brodbeck