Expert Advice – Glass Houses

Conservatories enable homeowners to enjoy the great outdoors without the hassles

Expert Advice – Glass Houses

Tanglewood Conservatories built a conservatory in western
Pennsylvania, designed as an addition to an 18th-century house.
The project incorporates a matching gazebo across the pond.

The hottest trend in outdoor living is extending the indoors outside, but some homeowners believe it’s a better idea to bring the outdoors in. That’s where custom-built conservatories enter the picture. Glass houses let you enjoy the garden when there’s a cold, early spring rain; in high summer when it’s too hot and humid to venture outside; on a blustery fall day when leaves are brilliant oranges and reds; and during winter snowfalls that turn the landscape into a silvery wonderland.
Conservatories are a definite cut above an ordinary sunroom constructed with ordinary glass windows. A custom-built conservatory has individual glass panels whose characteristics can vary widely.

If you plan on bringing tropical plants indoors for the winter, you’d likely opt for a glass that lets in light while reducing the risk of foliage burn. Some glass panels have insulating capacities that will allow you to use the room year-round; others reduce glare or deflect the sun’s rays in regions where summer heat can make glass structures uncomfortably warm.

Other considerations include the type of wood that will frame the conservatory and whether you want to use the room year-round, or perhaps for just three seasons. Typically, builders prefer mahogany for framing. While the wood is expensive, it’s considered the most beautiful, it requires minimal maintenance, it provides a good fitting for custom panels and it lasts for about 100 years.

Architects say that clients want conservatories for many reasons. Some people want the feeling of being outdoors without the hassles of insects, heat and humidity and summer downpours. Others may simply desire more living space and want to enjoy the landscape in the process.

The conservatory pictured on page 199 in McLean, Virginia, is a separate structure designed specifically to complement the very formal landscape. Architect Alan Stein, president of Denton, Maryland-based Tanglewood Conservatories, explains that the building not only contains a spa, but it also functions as a pool house, with changing rooms, a shower, bathrooms and a small kitchenette tucked across the rear length of the structure.

A freestanding conservatory by Tanglewood in McLean,
Virginia, is home to a spa, changing rooms and even a
small kitchenette

The spa is accessible through side doors several feet from the master bedroom suite in the residence, and through the main doors that line up directly on axis with the swimming pool. Just beyond the pool is an open-air cabana that contains a wet bar and barbeque grill.

There is no air conditioning inside the conservatory, but the tinted glass panels in the roof keep it cool. The mahogany woodwork is painted to match the trim on the house, and the floor of beige-colored limestone is almost the same hue. According to Stein, the major challenge of this project was to design a conservatory that would “fit in and play its role in this very formal landscape.”

From the front, it looks like a glass house that you might see in England. The rear part of building is actually a low brick structure with a flat roof designed to play off the flat putting green adjacent to it.

Conservatories in general can be very challenging to build, depending on their location. They require “sophisticated structural engineering” and must be able to withstand “strong winds, piles of now…or even earthquakes,” says Stein.

The mahogany woodwork is painted to match the trim on
the main residence.

John Schmitt, vice-president of Kingston Custom Builders in Fairfax Station, Virginia, agrees. He says building codes were revised after Hurricane Isabel hit the region in 1993, and plans must now “meet shear loads required for hurricanes.”

An essential component of the Kingston project in Potomac, Maryland, pictured opposite, is a custom-manufactured steel support structure that meets these new building regulations. When the conservatory was under construction, it looked like “half of Stonehenge,” says Schmitt. The clients wanted to replace an open-air deck one floor up from ground level with a room that would create an outdoor ambiance.

Hyattsville, Maryland-based architect Bernie Guay decided to retain the old patio’s rustic, random-rectangular slate flooring. On top of it, they built a structure with an 18-foot-high raised ceiling and tall glass windows with panoramic views of the landscape beyond. The hidden steel framework supports a copper roof, and inside, there are exposed wood beams, built-in window seats with storage, a high curio shelf and a skylight. Dormer windows on three sides, along with ceiling fans, keep the room comfortably cool in hot weather.

As a final touch, Kingston built in a barbeque grill, vented like a kitchen stove. Now, the homeowners have exactly what they asked for: a three-season space with dining and seating areas that feels just like a super-sized tree house.

A well-designed conservatory, says Stein, “changes the way people live and relate to their houses, because it always becomes the favorite room in the home.” He adds that glass houses improve homeowners’ quality of life because they create the illusion that you’re outside when you’re not. “It’s a magical feeling that’s almost impossible to describe,” he says. “There’s an unusual, very magical quality of light that draws people in, and they start to spend all their time in the conservatory.” That sounds like a reason to re-consider the deck and the patio and perhaps opt for a conservatory instead.

Jane Berger is a Washington, DC-based writer and publisher of

Kingston Custom Builders built a conservatory addition
onto a home in Potomac, Maryland, which features an
18-foot-high raised ceiling and tall glass windows with
panoramic views of the landscape beyond.

Kingston Custom Builders

This customizable cabana from Pennsylvania-based Vixen
Hill creates an outdoor sanctuary by the pool. The company
offers a wide selection of roof materials, from copper to
western red cedar.