New build flat is boiling hot. Feeling depressed

[FTBregret]

Just bought my first home, a small flat in London. Only just got keys last week and I hate it due to how disgustingly hot it is. Really regret it and feel so stupid for not knowing new build flats get this hot

So far I’ve removed all carpets (will only have laminate floors) all windows left shut during the day and kept all curtains closed to block out sunlight. Also tried fan with icy water in front and barely helped.

It’s still unbearably hot, thermostat currently showing 30°

I’m scared the worse is yet to come as I know it gets hotter in London and if we have a heatwave I will have to get an Airbnb or something.

I haven’t even got furniture yet so that will likely make it hotter too when I properly move in. How will I ever use the oven?

I’ve been looking at air con but as I’m leasehold with Clarion it’s very unlikely the split AC will get accepted. There is another type of water air con but looking at quotes it’s 5k which I can’t afford.

I’ve looked at portable AC but I only have hinge windows and hinge balcony doors (apparently it’s supposed to be for sliding doors??)

How are londoners in new build flats coping?

Do this

So far I’ve removed all carpets (will only have laminate floors)

I bet your downstairs neighbours will love you

Hi OP, I could have written your exact post when I moved into my new build flat in 2020.. I was so shocked and upset by the unbearable heat and stuffiness. It made me feel awful and so anxious.. Five years on and I’m pleased to say I have adjusted, it still gets very warm in the spring and summer months but I’ve worked out how to handle it.. basically black out curtains and blinds down in the day and windows going open at sunset then closed again at bedtime (sadly I’m in a noisy area so can’t keep the windows open all night, wish I could!). Also installed ceiling fans and excellent portable fans in each room as well as a portable AC for my bedroom when it’s really hot outside.. The coziness in the winter months and lack of need for heating (I think I turned the underfloor heating on once this past winter) is a big plus and as others have said, you do adapt. Promise!

Just checking what is underneath you - if you are on first floor is it retail units?

Similar situation here in new build south facing lounge and bedrooms all have floor to ceiling windows and I have to keep blinds closed all day at the moment at front of the house , windows open at the rear / back door open help with airflow but it hasn’t even been super hot today but I’m exhausted by it

This is good advice but its more 'close windows when its warmer outside than in, open them when its warmer inside than out' when we aren't experiencing a heat wave. Keeping the blinds down will help stop the sun heating the house up.

I honestly think the SE needs to start adopting shutters like on the continent. Yes blinds help but it would there is still solar gain through the glass compared to blocking from the outside of the building.

OP I had this exact situation!!!

The answer - BLACKOUT curtains and ajar all day. The normal curtains still let too much light and heat in.

My house is like this and it’s a 1940 ex LA semi. Just seems to retain heat. Things I’ve done that work well are reflective film on the south facing windows, thermal, silver backed blinds left closed in bedrooms all day, with windows open for air circulation. I’ve got ceiling fans everywhere (probably not an option in a flat though as you can definitely hear it in the room above through the floor) and a portable AC unit with a piece of Perspex cut to the size of the window and an AC hose sized hole cut in it. Works a treat. House is still warm, but there’s airflow (I’ve also fitted insect screens to open windows so I’m not eaten alive!). I run hot at the best of times so can’t tolerate anything above about 22 degrees - it’s currently 23 in my living room and 25 in my bedroom, but with the fans on and windows open, it’s quite pleasant.

Portable air con - Meaco do one that works with hinge windows. Get one asap bc if it gets hot they suddenly all sell out.

We had similar in a ew build flat it had underfloor heating which we rarely ever used.

Only had windows on one side as well. I found that having the windows open but blinds down (left am inch or so crack up) during the day with the bathroom extracter fan on worked the best. It was still beastly hot during a heatwave. As soon as it got to about 6 I'd throw the windows wide open raise the blinds and put a fan in front of the window to draw some cooker air in. The hum of the fans were annoying but we got used to it.

By Floor One do you mean first floor, not ground floor? What's beneath your flat then? I know some people refer to floors in different ways. Do you have adjoining walls to other flats?

I imagine your flat has some retained heat if it's been unoccupied for a while with no ventilation. It has been warm for a while.

Don't feel stupid. Imagine how much money you'll save in the winter on heating. Wonderful!

You probably will need blackout curtains or blinds and a portable Aircon and some fans.

But you'll work it out and you'll make your new home perfect for you

as far as I’m aware, insulation doesn’t differentiate between warm or cold?

Also, I’m not in London or a flat but I think it’s uncomfortably hot today and I know it’s not really that hot. I think it didn’t cool down much last night.

I’d put the carpet back and invest in air con if you can/are allowed.

The ideal scenario is to keep the sun off the windows. Is the building equipped with screens? If it's not, it will be worth looking into getting retractable screens fixed above the windows. You're only on the first floor, so this should be possible. It will make a world off difference.

Apart from that, windows open if the outside temperature is cooler and use a fan to circulate the air.

We have a portable air con, DH cut some hardboard to shape and put some clips on it to fit to the window frame, though Perspex as a PP used is a good idea as it's less noticeable and you can see through it a bit

It's pretty muggy outside today but your humidity is quite low which makes me think there must be direct heat coming from somewhere in the building that is drying out the air?

We have a new build house in the south east which overheats for most of summer. I have all the windows open at the moment and our house is currently 24 degrees yet the humidity is 64 as it's horrible and sticky. The heat gets into the walls and then becomes trapped and then when you close the windows again it just becomes radiant heat that warms up the house again.

What is underneath you? Have you felt the walls and floors for warm spots? Could there be badly insulated hot water pipes under floor or in the ceiling that supply the rest of the building but act like radiators to your flat?

Have you looked around the flat and felt temperature of the corridors?

I would be making a complaint and ask them to find the source of the heat. When did you buy it? as there were new regulations that came in that were supposed to prevent overheating. i.e external solar shading. You could challenge this.

Practical tips - bock sunny windows during the day but if the outside temp is lower leave the windows partly open to allow airflow. Maybe look into the reflective window film and air con. Turn off appliances you are not using. Keep the windows open at night where possible - maybe get insect screens.

Cooking is horrible in a warm house though and I wish I had bought an induction hob.

We try not to use the oven where possible.

If you have windows open you can have one fan pointing out and one fan pointing in right at the windows. Powerful fans, box fans if you can get them. Creates an illusion of air flow while being cheaper than a/c.

Yes agree, and a decent one is only about £150-200.

Also a dehumidifier will reduce the humidity which will make OP feel cooler too.

Sorry just seen you have only just bought the flat. I would complain and ask for an overheating assessment.

New build homes in the UK must comply with Building Regulations Part O, which addresses overheating. This regulation, introduced in 2021 and updated in 2022, aims to prevent excessive heat gain in residential buildings, particularly during summer months. The primary goal is to ensure comfortable living spaces while protecting the health and welfare of occupants

This is only if it’s hotter outside than it is inside! If it’s 30c inside then obviously it’s okay to open the windows as it’s nowhere near that hot outside at the moment.

Posters mentioning new regulation that's meant to prevent this

When did that come in? This place was finished in 2023. I'm alright but the people who are south facing had a really hard time last summer.

I think a lot of this is inevitable in flats, especially if you've got one above one below and two either side.

If there is new legislation, it may prevent going up to 35 but I've definitely seen the south facing flats hit 30 last year.

edit - we have some of the things that are supposed to help and they don't, but that's because the place is..a block of flats! And I agree that external shutters would really help.

I’ve had the heating AND log burner on in our draughty old Victorian semi. I’d trade with you!

Yeah we've got the heating on right now- northwest

Seems counter productive to build these heavily insulated properties that apparently are good for the environment by not using so much heating, when the occupants have to spend a fortune on a number of electrical gadget solutions to keep cool.

Also when people say 'make a complaint' who to?

Dont get a dehumidifier that will warm up the rooms.

Single aspect flats with no cross flow of air can be really tricky. They should really have been provided with comfort cooling and mechanical ventilation.