Kitchen extension - what can you do to make sure it stays cool?

[wewearshortshorts]

How do you build for a cooler house?

We are about to start a big kitchen extension and it will include switching from a boiler to a heat pump. There will be skylights and an enormous slide window out to the garden.

What can we do to plan for a cooler house?

Source radiators, maybe stelrad but might be somebody else, make them that, when installed with a heat pump, can switch to 'cooling' mode when needed.

perhaps change the plans and forgo the roof lights.

Have windows arranged so that a draft can flow through the house.
And shade. Think of ways to shade during peak summer hours.

Look at the orientation and where the sun comes in. If you must have huge windows facing south or west , or skylights, use solar blocking glass and external blinds. Include small windows that can open to let in a breeze as well as big doors.
It's a good chance to get this right, easier than retrofitting.

Keeping the sun off is the first thing.

A louvre patio roof. Like this https://www.stratco.com.au/au/patio--outdoor-living/patios--carports/outback-patios/outback-sunroof/

Or plan for hooks outside with pillars so a shade sail of some sort can be put up for months at a time. Or a retractable shade cloth.

I like our small windows above the sliding doors. Also planting makes a huge difference so if having patio outside see if you can leave planting pockets for small trees or shrubs to go into or tall grass. Think about a pergola too.

Double the insulation, triple glazed glass.

These are all really useful. Thank you.

Is there any value in putting a pond outside. I saw Kevin McCloud say that water outside is helpful for cooling outdoor air.

Paint the roof tiles with this special paint, it really helps. Also maybe remove all radiators.

No I don’t think it does.. It would only kill everything inside from absorbing all the heat.

Do you have windows at the top that are fixed?

Insulation, insulation, insulation.
Thermal glass.
Thermal shading.

Leave room between tops of windows or doors and the roof to fit a brise soleil or an awning.

You can get external shutters for Velux windows now.

See whether your roof lights can be made to open, even a crack. Hot air rises, so if you have an escape for it you create a rising draft which will keep the air flowing and cooler.

If you haven't built the foundations yet and are going to be ripping up much of the garden to do so anyway, consider putting a ventilation in pipe that is buried under. If the air goes in from the outside and flows underground where the temperature is less variable then by the time it reaches the house is cooler in the summer and warmer in the winter (en.wikipedia.org/wiki/Ground-coupled_heat_exchanger, sometimes called Canadian well).

I have been reading that heat pumps can also be cooling but I can’t find a supplier for the ones that cool.

Sliding doors with 6 opening small windows above. No fixed ones.

I googled hot and cold radiator and several sites came up, including this one. Not used them so no idea what they are like
https://www.theradiatorcentre.com/shop/energy-efficient-radiators/heat-pump-radiators/heating-cooling-radiators/

Daikin do domestic heat pumps, I normally come across them in commercial cooling applications so they probably do heating & cooling domestic ones

Agree with insulation - we have insulated plasterboard throughout our bungalow and it has not gone above 24c indoors even on the 5 consecutive days of 36c outside. Also something like an external sail or shutters to shade the windows too unless they're north facing.

You wouldn't really want air to water for cooling, heating yes. If you wanted both heating and cooling then check out air to air heat pumps. You don't say if the property is detached or what, but if you wanted air to water heating and then a separate air con heat pump you can't have both under permitted development unless the property is detached. If semi or other planning permission is needed for two heat pumps.

It’s a terrace. We have planning permission for the heat pump but not for cooling.

Make sure at least one of your skylights opens for ventilation, ideally all of them. Don’t make them really large no matter how tempting. If they are Veluxes get these.

Have an awning above your big glazed doors. Or at least a brise soleil. Blocking sun before it hits the glass is much more effective than blinds inside.

Specify solar blocking glass for everything. Consider putting UV blocking film on the skylights too.

We have

5.5 bifolds - integral blinds block light to prevent greenhouse effect.

Two large fixed lanterns - wished we got an opener(?) We do have blue reflective glass but we will be adding motorised blinds- these are expensive but I now think they are essential. You could probably do it with regular roller blinds and a hook on a shank!

Budget for covering any glass.

We added an extra side door last minute for air flow.

As others have said up thread I am also considering an awning as we have a set of French doors also that are a weak spot.

We have porcelain floor which is nice and cool underfoot but also have UFH for winter.

Recently I was admiring some renovations near me all gone for double height glassed pitched porches and some rears and thought mine looked a bit dated and kind of boring but goodness I am pleased I don’t have that much glass.

I did hear on R4BBC that cooling is a separate unit linked to heat pump. Not sure what that meant though.

All your glass needs to be protected from the sun from the outside, i.e. as in France/Spain/Greece etc, with shutters.

For retro fitting we have just put bamboo blinds over the outside of our kitchen window and french doors (south facing). They have really worked well and kept a lot of the heat out for just over £100 (Amazon). Plus we can still see a lot of the garden.

Definitely get roof lights that open. Fixed ones are a pita if flies get in, as they congregate up there! If I were doing my extension again I'd get proper Velux ones with blinds.

We had an aircon unit installed and are so glad we did. It can also be used for heating and as a dehumidifier. If you can get a heat pump that cools as well then go for it.

We have a heat pump and paired it with a fan coil unit. Note this is separate from using the heat pump to run cold water through your underfloor heating. That's often not advised as it can create condensation under the floor. It sounds like it might not be permitted for you for some reason too.

Fan coil units do use the heat pump in reverse - the heat pump cools a tank of water instead of heating it. It sends that cold water around to a fan coil unit. The cold water runs through pipes in front of a fan which blows over the pipes. The air is cooled as it passes over the pipes. In the hot weather recently it has taken our kitchen from 26 to 20 degrees. They are brilliant. We used the rebate scheme and I don't think that you are prevented from using the heat pump this way.