Building's architectural editor lives in a Victorian house. Read his diatribe on modern windows and you'll understand why.

In an increasingly important sense, our Victorian and Georgian forebears were true modernists.

No, I'm not talking about the thick worsteds, starched linens and multiple petticoats they trussed themselves up, leaving only a nose, two eyes and perhaps a voluminous beard peaking out. Nor about the black smoke and stench belting out from their homes and workplaces. How enlightened we are nowadays that we dress lightly and casually, allowing our bodies to absorb all the fresh air and sunshine around us. And if our suntans are looking a bit jaded, well, we just jump in budget flight to the Med, India or Thailand and loll around on the beach.

And in our homes, warmth, bright lighting, electric fans and sun-lamp all come to our service at the flick of the switch. But wait a minute! Aren't the genuine articles available free of charge and with no risk of global warming - through our windows?

Sadly, not at all. One thing Britain's spec housebuilders are particularly energetic about is to squeeze down windows in living rooms, bedrooms and kitchens, let along bathrooms, to just letterbox size.

Earlier generations of spec housebuilders in the 19th, 18th and even 17th centuries took a much more enlightened, environmentally friendly approach. By borrowing sash windows from across the water in Holland, they flooded their habitable rooms in daylight that modulated with the time of day, the weather and seasons. Stretching vertically from low sills to high heads, they threw an even spread of daylight from the front to the back of the room, and their splayed jambs softened any glare that might be created. And the smaller a room was, the more vital was it to borrow as much a sense of space as possible from outside through a large window.

The classical styles with ornate mouldings favoured by Georgians and Victorians don't come into the argument. We can design and make generous windows true to modern technology and materials.

Just don't let's pride ourselves about our enlightened, healthy, nature-loving lifestyles and our devotion to sustainable development. According to our own progressive, modern principles, the Georgians and Victorians did it much better. One thing that we can say for certain about contemporary spec-built houses with windows the size of letterboxes. Within a few years their poky, gloomy rooms will be condemned as uninhabitable slums and pulled down, though, god forbid, surely not in the interests of spec builders' profits. And exactly how sustainable is that?