Newly constructed apartment owners are expressing concerns that their homes have become intolerably hot, grappling with temperatures soaring to 34C during the UK’s fourth heatwave.

Residents at Leaside Lock, a high-rise development in Tower Hamlets, east London, were so affected by the intense heat last year that they resorted to placing warning signs in their windows stating: ‘DO NOT BUY THESE FLATS. TOO HOT’.

Temperatures are set to hit 34C today, with amber heat health alerts in place for London and the south east until Wednesday.

Tenants have described the conditions as ‘unbearable’ as a fourth heatwave gripped the UK this week. 

Meanwhile, those living in a nearby block of flats in Three Waters have seen their thermostats reach almost 30C.

Sandra Monteiro, 41, said temperatures inside her 11th-floor home have not gone below 27C for the past two months.  

‘It feels like you’re in a trap,’ she told the Guardian.

The conditions, she added, had left her feeling ‘out of breath’ and ‘exhausted’, with it also causing her frequent headaches. 

Lucian Ho, a 21-year-old student residing on one of the upper floors of a 28-storey building, mentioned he struggles to rest due to the heat, with his only respite coming from a partially open window that provides little air circulation or breeze.

Social media community groups in areas like Greenwich have turned into thriving hubs where residents are urgently seeking advice on coping with the intense heat.

One local asked: ‘Is anyone else struggling in their new build flat with the heat? I just moved into one recently and the heat is unbearable. Even with the windows opened and a fan. Any tips for coping in the summer living in a new build please?’

And their neighbours were quick to offer suggestions including pulling down the blinds and buying air conditioning units. 

But others were just as frustrated, commenting under the original post that the flats are ‘awful’.

Talie Eid said: ‘Honestly, they’re awful. Never warm enough in winter (we don’t have standard radiators) and too hot in summer. Keeping blinds/curtains closed during peak time does help a little. We ended up getting an air cooler as fans not enough.’

While another said they had moved from a Victorian-era house to a new build and regretted the change, adding their new flat was affecting their mental health. 

They wrote: ‘It’s actually starting to affect my health and the health of my pets. I’ve always lived in a Victorian and made a big mistake moving into a new build. It’s unbearable. I feel for everyone who is going through this. It’s horrible. 

‘They build them quick. Charge high rent but don’t build them properly with good ventilation. It’s very frustrating.’ 

Peter Veress suggested the only way to escape the heat was to splash the cash and invest in an air conditioning unit. 

He said: ‘I was living in a flat a few years back, and in our living room in summer the temperature went up to 37 degrees even though curtains were always closed during the day. 

‘We bought an Aircon for around £300 and that was helpful when it was running, but as soon we switched off, you felt the heat. As others said, it’s summer. Without an aircon in a flat you are cooked.’

Another resident said that her and her family simply stopped cooking during the summer, preferring to eat rotisserie chicken and salad on the river bank than make their flat hotter by turning on the oven. 

But the problem isn’t new and Londoners have been seeking advice and ways to mitigate the extreme temperatures inside their flats for a few years. 

A Reddit thread from 2023 saw one homeowner who had recently moved to their new build flat complain of only having two windows which open ‘a few inches’.

The homeowner said their flat could easily reach 28.5C and even at 3am they had seen their thermostat jump up to 27C.

In the post they wrote: ‘I moved into a new built flat a few months ago and while everything was great at the beginning, I’ve currently run into a bit of an issue in this weather.

‘Basically the flat has windows on only one side in two separate rooms (living room and bedroom) and as such there’s little to no draft. The window in the bedroom only opens a few inches as well making it even worse.

‘Currently, while it’s a lovely 21 degrees outside here in London, my flat is at a less lovely 28.5 degrees. Even at night, at 3AM I checked the thermostat, the temperature was still 27 degrees.

‘I haven’t been able to sleep properly for over a week and last night I only slept an hour maybe. I just can’t seem to sleep properly because of the heat.

‘I’ve got a fan and an air cooler that I put water and ice blocks in so it fans cooler air around the room. Still, the temperature didn’t drop below 27 degrees and I’m at my wits end.

‘I can’t install an air conditioner I think as there’s no space on the outside of the building (and the housing association doesn’t allow it) so I’m trying to figure out what to do or I’m going to have to crash on a friends couch for the next couple of days.

‘Another issue that’s adding to the misery is the fact that the flat backs out onto a busy railway and there are probably 50+ trains passing per hour from 4:30 AM until 1 AM. 

‘The windows are soundproofed well so the noise isn’t a problem when I keep everything shut, but the moment I try and air out the heat, I’m greeted with constant noise that a normal human being wouldn’t be able to sleep through.’

Lorraine Thomas, director of property company View From My Window, explained that the flats were designed with energy efficiency in mind.

With extra insulation and thick windows, the flats are warm in the winter and many residents won’t even need to put their heating on.

But during the summer the same insulation causes the flats to heat up to extreme levels. 

She told the Daily Mail: ‘Windows were put in these flats to provide natural daylight but what’s happened is a conservatory effect where it’s hotter in summer and colder in winter. 

‘The size of windows were designed to save on bills but now they are too hot.’

She added that fire resistant insulation has added extra layers to buildings already quite energy efficient and said the more flats piled in to blocks, the hotter each home will be.

‘Before it wasn’t so much of an issue but with new fire safety insulation that’s resistant, it’s added extra heat.’

The building expert also attributed London’s dense population to hotter flats, explaining that many of the high rises built now are close to roads, bus routes, train lines and commercial buildings with lots of traffic and footfall and limited green spaces. 

Ms Thomas added: ‘Dense population and area, there’s nothing sparse and the overcrowding of blocks with too many flats – it all helps to capture the heat.’

The company owner explained that the only way for homeowners to cool off was to invest in air conditioning, explaining that new build windows are designed with health and safety in mind and don’t open very far limiting through drafts. 

‘More and more people will have to get air conditioning because opening windows just doesn’t do enough to help,’ she said.

And it seems Londoners are way ahead of Ms Thomas as recent data from Checkatrade has revealed that demand for air conditioning units has increased by a quarter. 

Interest in installation for units has risen by 23 per cent on last year as the heatwave pushes homeowners to consider more ways of keeping cool this summer. 

It comes as parts of Britain are set to hit 34C with health alerts in force amid water shortages in England.

The country’s fourth heatwave of the summer will be at its peak today, with Berkshire, Oxfordshire, and the outskirts of London set to see the highest temperatures.

An amber health alert came into force at 9am for the Midlands, South East, East of England, and London. There are yellow alerts in place across the rest of England.

Today will be the fourteenth day that the mercury has risen past the 30C mark, with the heatwave set to continue for the rest of this week. Temperatures are expected to hit 31C on Friday.