Why on earth do conservatories cost so much to build?

Aluminium Victorian conservatory installed by Hazlemere in Beaconsfield Bucks
Aluminium Victorian conservatory installed by Hazlemere in Beaconsfield Bucks
The simple answer is that conservatories require almost as much design, planning, materials and work as a full blown extension to any home. For starters, you surely will want your conservatory to have foundations as good as if they were for an extension, given the desired outcome is the same, a functional extra room.

Until I joined Hazlemere Conservatories in Buckinghamshire, I had no appreciation of the amount of investment and time required to build a professional conservatory base and foundations. The amount of building work required before a conservatory frame can be erected is enormous, compared to the actual installation of an aluminium or UPVC double glazed conservatory. Dependent on the size and complexity of a new conservatory, the building works can take 2-3 weeks, whereas the rest of the conservatory can then be erected and finished within 2-3 days.

I had no appreciation of the high percentage of costs of building a conservatory that are spent in the ground. In very round figures, when buying a conservatory the building works represent about a third of the total costs, the windows and doors cost about a third and the conservatory roof the final third.

To avoid long term disappointment, it is important not to compromise in any of these areas, particularly on the glazing in the roof, which, in my opinion, is what will make or break your conservatory project, and determine whether or not you can use the room all year round. It is essential to have as much ventilation as possible in the summer, so ensure you have sufficient opening roof vents for the size of your conservatory (as these act as chimneys, venting away the hot rising air on sunny days), along with enough opening windows and doors to provide extra ventilation during a hot summer.

Obviously, the more opening roof vents, windows and doors, the more your conservatory will cost, but there is no point in cutting corners if such short sighted measures leave your conservatory uninhabitable in either the winter or summer. Likewise, Celotex floor insulation costs extra, but you will notice the difference on cold winter days if you have not properly heated or insulated your conservatory, only gone for “standard” double glazing, rather than highly thermally efficient glass (yes it costs more!) and not invested in a reflective coating on your conservatory roof, like Pilkington’s Blue Activ self cleaning glass.

If your intention is to be able to use your conservatory all year round, then you will probably need to invest more than you first planned, as you don’t want to invest your hard earned savings in a nice looking conservatory because it was the “cheapest quote”, only to find it’s environment on cold winter days and sunny days unpleasant and unusable.

Over the last 12-18 months I have met so many conservatory owners in Hazlemere’s High Wycombe Showroom, who opted for a “cheap” polycarbonate roof, simply because they could not afford a double glazed one, who have subsequently regreted not waiting till they could have afforded it, as retro fitting a new conservatory roof and double glazing, can be almost as expensive as building a UPVC conservatory. Other clients, with a southerly aspect who did not invest in solar controlled double glazing, find themselves “having” to fit conservatory roof blinds with a reflective top coating, or even swap over the sealed units for Pilkington Activ Blue or Neutral glazing solutions, an extremely expensive exercise.

The bottom line is that if you want to have 24/7 use of your conservatory it is far more economic in the long term to invest upfront when building a new conservatory, however hard it may seem at the time, as it will be far more financially painful and time consuming if you do need to retrospectively spend and spend to try and put right, what you wish you had ordered in the first place.


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