ᐅ End-Terrace House from 1915: Photovoltaic System?

Hello everyone,

We were incredibly lucky to purchase a great end-terrace house (heritage protection only on the exterior) in a fantastic neighborhood.
Built in 1915, but the structure is in excellent condition since it was built before the war.
No moisture in the basement, and the roof is dry.
Heating was provided by gas individual heaters in each room, but these have already been removed.
Living space is about 110 sqm (1,184 sq ft), garden area 450 sqm (4,844 sq ft) in the beautiful Palatinate region.
A gas connection is available.

We now want to renovate and already have an energy consultant who will also oversee the construction supervision.
Initial feedback from the energy consultant:
- Photovoltaic system on the south-facing roof without shading
- Thermal buffer storage recommended
- Ventilation system combined with an earth tube (seems to replace a split air conditioning unit? Does anyone have experience with this?)
- Ceiling heating

What I am considering:

- Photovoltaic system on the south-facing roof
- Thermal buffer storage
- 10 kWh electric storage battery
- Underfloor heating on the ground floor
- Low-temperature radiators on the upper and attic floors
- Split air conditioning units recessed into the ceiling in the living, bedroom, and guest rooms

We will fully equip the house with KNX automation, including modern and up-to-date control of the heat pump and storage system.

What would you suggest adding, combining, or improving here?

We are in a very comfortable financial situation, in our early 30s, and want to “do it right” this time.
The exterior of the property must be preserved, except for the photovoltaic system on the roof, as environmental protection takes priority over heritage preservation.

Thanks for your suggestions and information.

Best regards

mayor333 schrieb:

We were incredibly lucky to purchase a great end-terrace house in a fantastic neighborhood (historic preservation applies only to the exterior).
Built in 1915, but the building structure is in excellent condition since it was constructed before the war.

Joker. 1915 was during the war.

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11ant schrieb:

Funny guy. 1915 was during the war.

Maybe the house is in the USA? They only joined in 1917.

@mayor333 Somehow your ideas about split air conditioning / underfloor heating don’t quite fit with the primary energy demand (PED) using ceiling heating? Or do you want to go for a wild quirky mix?

@mayor333 Congratulations! I notice there is no mention of improving the thermal insulation of the building envelope. Since the facade cannot be altered, for example, calcium silicate boards could be installed on the inside of the walls. Is insulation planned for the basement ceiling and roof? Is the roof airtight? What condition are the existing windows and front door in?

SoL schrieb:

Maybe the house is in the USA? They only joined in 1917 as a replacement team.

@mayor333 Somehow your ideas about split air conditioning / underfloor heating don’t really fit with the EEB concept using ceiling heating? Or are you aiming for a wildly mixed system?

EEB wants to first develop a concept, and we will meet again in June/July.
Personally, I would rule out ceiling heating, but I would like to experience it live during winter to see how it feels.

BobRoss schrieb:

@mayor333 Congratulations! I notice there are no considerations listed for improving the thermal insulation of the building envelope. Since the facade cannot be altered, it could be worked on internally with calcium silicate boards, for example. Is insulation planned for the basement ceiling and roof? Is the roof windproof? What is the standard of the existing windows and front door?

On the gable end of the house, 6cm (2.4 inches) of insulation including plaster is allowed.
The roof is currently uninsulated; a 10cm (4 inches) external roof insulation will be installed. This means removing the roofing, reinforcing the rafters for the photovoltaic system, and then reroofing (the attic will also be converted).
The basement ceiling cannot be insulated at the moment due to a height of 1.90m (6.2 ft); the basement floor was concreted over several years ago.

The front door needs to be replaced, as does the garden door. The windows date from 1988, are double glazed, but in excellent condition. They were completely overhauled about 4-5 years ago, including adjustment and new seals.

mayor333 schrieb:

- Thermal buffer tank advisable
- Combine ventilation system with earth-air heat exchanger (Does this possibly replace a split air conditioning unit?! Does anyone have experience with this?)

The earth-air heat exchanger is used with ventilation systems and air-source heat pumps for pre-conditioning the outside air. The air is passed through a gravel bed underground.
In summer, it cools the air; in winter, it slightly warms it -> mild climate control without an air conditioner in summer and warmer air for the heat pump in winter, resulting in lower electricity consumption.
In reality, the additional effort for the earth-air heat exchanger is much higher than the benefit for modern heat pumps unless the excavation pit is already available (new construction). Especially for smaller living areas, it is like using a sledgehammer to crack a nut regarding the energy savings effect on heating.
For cooling in summer, it is nice if you want to avoid an air conditioner and just rely on mild temperature control.

mayor333 schrieb:

Split air conditioning units recessed in the ceiling in living, bedroom, and guest rooms.

That contradicts the earth-air heat exchanger. It’s either a ventilation system with earth-air heat exchanger for temperature control or split AC units. It depends on your preferences, the region, and heat loads (south-facing windows, shading, etc.) in summer.
If you install split AC units in every room, you might as well skip the other heat pump for heating and use just the AC units to heat. This also saves the expensive ceiling heating system.

mayor333 schrieb:

EEB wants to develop a concept first, and we will meet again in June/July.

Yes, that should be created first, ideally coordinated with you, your budget, and your requirements. They probably mean an individual heating and energy efficiency plan (iSFP), hopefully.

mayor333 schrieb:

The gable end of the house may be insulated with up to 6 cm including plaster.

So about 4 cm (1.6 inches) of actual insulation thickness. Not much, and the rest of the house will then remain as existing masonry.
Depending on your goals, more may be necessary. If you only want to meet KfW efficiency house monument standards, a lot can be justified, and this is usually sufficient. In all other cases, the entire building envelope needs to be upgraded—from basement ceiling to facade, windows, and roof.
Whether this is feasible and reasonable with your budget should be explained by the EEB.
If you’re renovating the interior anyway, internal insulation is often more sensible than renewing the exterior plaster and adding 4 cm insulation on the gable end. Avoid calcium silicate insulation here; instead, use wood fiber insulation. It has only advantages (cost, thermal conductivity, heat capacity, ease of installation). Then install wall heating behind it, which saves you the extra effort of ceiling heating and removes any (mostly unfounded) concerns about harmful condensation risk.
Otherwise: Built in 1915 -> double-layer masonry with cavity? If that is the case, cavity injection with insulation material is usually the most practical solution.

mayor333 schrieb:

Front door and garden gate need replacement. The windows are from 1988, double-glazed but in excellent condition.

Double glazing from 1988 is a completely different world compared to double or triple glazing in 2024. Under heritage protection, depending on the shape and requirements, replacements are usually more expensive, but it may be worthwhile to just replace the glass rather than the entire window. The EEB should be able to advise you on this.