Updated 9 June 2026 · 9 min read
If you live in London or Hertfordshire, you likely know the “conservatory struggle” all too well. It’s that beautiful glass room you paid thousands for, yet it stands empty for nine months of the year. In the summer, it’s a greenhouse that could wilt a cactus; in the winter, it’s a walk-in freezer.
At Presswarm Windows, we’ve been family-run since 1973. For over 50 years, we’ve seen homeowners try every “quick fix” in the book: thick curtains, portable heaters, blinds — only to realise the problem isn’t the furniture, it’s the roof.
The truth is, many older conservatories across London were built with materials that simply aren’t up to modern standards. Here are the 7 most common mistakes homeowners make with their conservatory roofs, and why a professional replacement is the only real cure.
1. Holding on to outdated polycarbonate
Most conservatories built in the 90s and early 2000s used polycarbonate: a corrugated plastic that was cheap and lightweight. While it served a purpose then, it’s the primary reason your room is unusable today. Polycarbonate has virtually zero insulation properties — it lets heat out in winter and traps solar radiation in summer. Poorly insulated conservatories can lose up to 30% of their heat through the roof alone.
The fix: We replace these dated plastic sheets with high-performance, A-rated glass or solid tiled roofs. This creates a thermal barrier that keeps your room at a consistent temperature, effectively turning your conservatory into a year-round living space.
2. Thinking a “patch” will solve recurring leaks
It starts with a tiny drip during a London downpour. You hire a handyman to slap some sealant on the flashing, and it works — for a month. The mistake here is treating the symptom rather than the disease. Recurring leaks are often caused by slipped panels or perished gaskets that have reached the end of their lifespan. When a roof begins to move structurally, no amount of silicone will keep the water out forever.
The fix: A full roof replacement ensures all seals, flashing and drainage systems are brand new and professionally fitted. Because we use our own directly employed, time-served installers — no subcontractors — we guarantee a watertight finish that actually lasts.
3. Ignoring the “London noise” problem
If you’re near a busy road or under a flight path, a polycarbonate or thin glass roof acts like a drum skin. Even a light rain shower can make conversation impossible, and the constant hum of city traffic can ruin a quiet Sunday morning. Homeowners often try to ignore this, but acoustic discomfort is one of the top reasons people stop using their conservatories.
The fix: By upgrading to a solid roof — or adding our specialist acoustic secondary glazing to the windows — you can reduce external noise by up to 80%. Imagine sitting in your conservatory during a thunderstorm and barely hearing a peep: that’s the difference quality materials make.
4. Forgetting about your energy bills
In an era of rising energy costs, an uninsulated conservatory is a financial drain. If you have to keep a radiator running constantly just to make the room bearable, you’re essentially throwing money through the roof. Many homeowners mistake “heating the room” for “fixing the problem.” If the roof doesn’t have a low U-value (the measure of heat loss), that heat is gone in minutes.
The fix: Our replacement conservatory roofs are designed with thermal efficiency at their core. By significantly lowering the U-value of the structure, your home stays warmer for longer — reducing the strain on your boiler and your wallet.
5. Trusting subcontractors over craftsmanship
This is perhaps the biggest mistake of all. Many large national companies sell you a “bespoke” roof and then hire anonymous subcontractors to fit it. These installers are often paid by the job, leading to rushed work, messy finishes and skipped steps in the sealing process.
The fix: At Presswarm, we are Which? Trusted Traders and FENSA registered. Every person on your property is a direct employee. This means we treat your home as if it were our own, with three generations of craftsmanship backing every screw and seal.
6. Overlooking the “orangery” upgrade
When people think of a roof replacement, they often assume they have to stick to the exact same style. The mistake is not realising that a roof upgrade is the perfect time to transform the character of the room.
The fix:You don’t have to settle for a basic glass lid. We can often incorporate internal pelmets and brick pillars to give your conservatory the feel of a substantial, light-filled orangery. It adds a touch of luxury and can significantly increase the resale value of your London home compared to a standard glass box.
7. Assuming you need planning permission for a new roof
We often hear from customers who have put off a replacement for years because they dread the paperwork. They assume that changing a glass roof to a solid tiled one requires a lengthy battle with the local council.
The fix:In the vast majority of cases, replacing an existing conservatory roof falls under Permitted Development. Since the footprint of the building isn’t changing, you rarely need planning permission. We provide honest advice and guide you through the regulations, ensuring everything is fully compliant and guaranteed.
Is your conservatory ready for a change?
A conservatory shouldn’t be a storage room for old gym equipment or a place that’s “off-limits” in August. It should be the heart of your home — a bright, airy space where you can actually relax. Whether you’re in the heart of London or a leafy Hertfordshire suburb, our team is here to help. We don’t do pushy sales or “buy it now” pressure — just straightforward, professional advice based on 50+ years of local experience.
A new conservatory roof can work wonders for that room, but it can also make sense to improve the rest of your home’s comfort at the same time. If your original windows still let in draughts or outside noise, secondary glazing is a smart next step that further boosts insulation without changing the look of your property.
Ready to reclaim your room? Get a no-obligation quote today or contact our team for friendly advice. We’ll treat your home with the respect it deserves, ensuring a tidy, professional installation that’s fully guaranteed.