What is an alternative to blinds on large windows to protect your home from overheating in the summer?
We are planning a new building and are with the floor plan, building application, etc. completely through and could start directly, if not an expensive showstopper by the energy consultant would have arisen.
Due to the offset in the terrain, our living / dining room and adjoining semi-open kitchen is lower. Ceiling height is about 3.8m. Windows to the garden two 3x3m west, and another large corner window in the east. Now it said that we need exterior jalousies on all windows of the critical space. Increasing the Ug/Uw class of the windows would not change this. Window/room ratio about 40%.
Fact: this is not possible in terms of cost.
Current proposal: no windows, just a glass door with a skylight. Ergo: we can no longer look into our garden and that is absolutely not an option for us.
If it is only about this critical space. What else can be done?
1) Ventilation system is in, increased night ventilation is considered. Unclear if with heat recovery.
2) District heating or air-to-water heat pump.
Are there models that could integrate low cost air conditioning for only 2 rooms? Then I would have an option for 15/20 days a year. Does anyone have any idea how this would compare in cost to 6 exterior shutters?
We keep hearing only shutters or "no" windows/glass doors in. And feel massively backed into a corner.
We would be so grateful if we could get an idea here.
As for your problem: Be grateful to your energy consultant. It saved you from a major construction mistake. An 18-square-foot room with a west-facing window can easily become virtually uninhabitable within six months. Unless you like your living room to be over 30 degrees.
You can forget about air conditioning through KWL, the volume flows are just too low for that.
Cooling through underfloor heating can give you 1-2 degrees more.
As an air conditioner you will need more cooling power. Solar gives about 1 kW per square foot. Even if you subtract 50% because of the angle drop and covered windows, you get about 9 kW. That's a very large furnace at full power!
You only have two real options:
A much (!!!) smaller window.
You're not serious, are you? You're building a house with 3.80 m room height (!) and now the unplanned blinds blow up the budget? Apart from the fact that you actually plan something like that from the outset with appropriately aligned windows, how do you want to counter all the other "surprises" during the construction period?
An air conditioning system including installation will also cost a few thousand euros, that's for sure. Might be a bit cheaper than six shutters, but I expect the difference to be marginal.
I think you simply have no choice. If you want the windows, then you have to shade them. I would do that for the surfaces to protect the furnishings. And with more than 20 square meters of glass surface, the room heats up even in normal sunny weather – that's not just 20 summer days a year.
Actually, you should thank your energy consultant. The summer thermal protection is often swept under the table and here there are often questions about what you can still retrofit with the problem.
If the sun's rays should stay outside, the only options are small windows, exterior shading (much more efficient than interior shading) or a large roof overhang that must fit the house. I personally find external venetian blinds the best option here. On the one. On the one hand you have the shading and on the other hand still the transparency to the outside. With shutters you have just on or off or light or dark.
Be glad that the energy advisor pointed this out to you.
Otherwise you would be here again next summer and ask for funky solar handicraft roller shutters.
Now is your chance to get it right now.
If you have no money for roller shutters, a large roof overhang might really be the best.
Or a cheap canopy in front of the large windows or awning.
So care for small or too few windows.
Even if there is no direct sunlight, window openings illuminate the room in a completely different way than lamps could. I wouldn't let that be taken from me.
Nowadays, these sliding/folding blinds are built with wooden slats on the outside. It might look pretty good, I don't know if it's cheaper than exterior blinds. We have exterior blinds everywhere, and it's a distinct difference from roller blinds in the old house when the sun really shines. A very cheap option would be vertical awnings without side rails, but that doesn't seem reliable to me. Perhaps a well-placed awning outside would help, too, especially if you're building on a slope.
But honestly: I wouldn't skimp on shading in a new building, but compromise elsewhere. If you build such a half-price solution now, as climate change intensifies, you'll be putting a lot of money into fixing it in a few years. That's my expectation.
You won't find a cheaper alternative to exterior shading (exterior blinds, roller shutters, curtains, ...).
And even if you reduce the size of the windows, they still need to be shaded.
THANK YOU to everyone who left comments.
We have made the following conclusions:
— All windows are reduced in height by 50 cm.
— The two west windows are reduced from 3x3 to 2x2.5 and have exterior shutters.
— The corner window on the northeast is shortened by 1.5 to the north and retained.
— In the calculation, the protrusions of the building could be used for shading.
Hopefully all together this helps.