Insulation of historical facades: Thermal insulation for old houses, preservation of historic monuments, etc.
For many people, modern thermal insulation and the legal obligation to modernise, including a renovation timetable for residential buildings, which is partly compulsory in Germany, cannot be combined with an old farmhouse or a listed building.
Insulation disfigures old buildings and robs them of their historical, authentic appearance, is the accusation often levelled against Styrofoam panels and other facade insulation. But there are also alternative insulation techniques that can be used to preserve the facade – despite thermal insulation. Here is a guide to the insulation of historical facades.
Keep an old face: that’s the way to do it!
The insulation of historical facades is only recommended from the inside of many buildings. On the one hand, because the protection of historical monuments does not provide for a change in the external appearance of the house, and on the other hand, because the owner would certainly like to preserve the house.
Therefore, you should not do without the insulation of historical facades because of their appearance, but instead of external insulation, simply install internal insulation.
Depending on the amount of work required on the exterior wall, this will reduce costs and save you not only energy for heating the house, but also money in the future! This is particularly recommended for buildings with half-timbered or surrounding buildings, clinker brick buildings, quarry stone facades, etc.
Brick buildings: Core insulation or WDVS?
Especially in the north of the Federal Republic of Germany as well as in Denmark and other countries in this region there are numerous houses with clinker walls.
The red or brown facades can belong to a listed house or should simply be preserved for the sake of appearance. If this is the case, core insulation can be applied. For this purpose, insulation material consisting of mineral rock and plastic is inserted into the space between the double-shell brick wall.
Alternatively, a thermal insulation composite system (WDVS) can be installed on the outside of the brick wall if it is not a listed building. If this is fitted with facing bricks, the appearance of the exterior is retained to some extent.
Insulating a facade with stucco: is that possible?
If your house or building has stucco decorated facades, then the protection of historical monuments also plays a role for the right measure of insulation.
This is because the preservation order only provides for a repair and the necessary addition to the shape of the facade. If these regulations do not apply, then a stucco substitute made of insulating material can be created in order to realise the external insulation of the facade on the historic building.
If the original facade must be retained, then internal insulation is the best alternative. Polystyrene or mineral fibre boards are recommended for straight walls. If you have rounded interior walls or an oriel for insulation, then use cellulose for spraying.
Insulation of historical facades: it is possible!
You see: It is quite possible to efficiently insulate historic facades. If it is not possible from the outside, or if this is not an option, then the insulation can also be implemented from the inside.
Although facade insulation is most effective when it is applied to the outside wall, there are also significant savings in energy and heating costs from inside the house wall insulation.
You should also know that it is not only the insulation of historical facades that is beneficial to the thermal insulation of an old house. There are several other points on the list of renovation measures that you should also keep an eye on and discuss with an energy consultant.
Reading tip: Protection against graffiti
Further measures for greater energy efficiency
Facade insulation in historic buildings is only one of many components for increasing energy efficiency.
Other measures in addition to the insulation of historic facades include roof insulation, replacement of windows and doors, modernisation by installing a new heating system, cellar insulation and so on. In the end, even in an old farmhouse, energy savings of up to 80 percent can be achieved with these measures.
Naturally, a professionally sound energy consultation with the preparation of a renovation plan and subsequent support from the KfW Bank or the BAFA are useful in this respect. The KfW Efficiency House Monument for Private Individuals programme (grants 430 and 431 as well as loan 151) is recommended here.
Renovation of old buildings FAQ: Questions and answers
With regard to the renovation of old buildings, there are some mistakes and misinformation which deter some homeowners from renovating old buildings.
However, builders should bear in mind that this supposedly important information is usually only rumour or at best outdated. Therefore here is a small FAQ (Frequently Asked Questions):
Is a new building better than the renovation of an old one?
For a new building often more energy as well as money must be raised. Because the shell alone, which is already there even in an old building that needs to be completely renovated, costs a lot. In addition to the charm that a historic building has, you also benefit from the investment, especially since you can obtain subsidies and KfW loans for it.
Can an old building become an efficiency house?
For many this seems impossible, but it is possible. Even a historic old building can become a passive house if all necessary measures are taken.
This of course requires not only the insulation of historical facades, but also the replacement of windows and doors, roof insulation, a modern heating system and other work. But in the long run, this is extremely worthwhile.
Are you paying for the renovation of old buildings forever?
For some, the measures seem endless, so they seem to last forever and will swallow up money again and again. But we have already mentioned the most important and biggest points.
These are quite manageable, so that the renovation of old buildings is not a bottomless pit! Certainly there are many things to consider, but you can hire an energy consultant for a renovation schedule and construction supervision.
Doesn’t the danger of mould increase after the renovation?
Here, the question is based on a false assumption: many believe that an old house “breathes”. This is not true, as the cracks, gaps and holes basically only allow valuable heated air to escape and, as a side effect, moisture.
In an insulated house with a vapour barrier, you can also get rid of this humidity by manual ventilation or a ventilation system.
Does the facade have to be insulated first?
No, even roof insulation and the replacement of windows can initially lead to an extreme increase in energy efficiency.
However, there is often an obligation to modernise the facade if more than 10 percent has to be renewed (replastered). But even this can be done after roof, windows and the like.
Facade paint from proPERLA
In addition to the above-mentioned work, we recommend our facade paint, the clinker and brick cream, the horizontal barrier for walls and rocks and the heat insulation paint from proPERLA for facade insulation.
In addition, for professional use, we offer roof coatings (roof paint) and other products that are water-repellent, breathable, self-cleaning and individually applicable. Just take a look at our homepage properla!