Plantation shutters in Compton

Out-of-square openings

With 77% of homes built before 1980, many openings have had decades to settle. Measure each one's width at the top, middle and bottom, and both diagonals. If the diagonals differ by more than about ¼ inch, add a mounting frame in the designer, or choose an outside mount so the shutter covers the uneven edges.

How to measure

Plaster walls and deep casings

30% of homes date from before 1950, when walls were plaster on lath and windows sat in deep wood casings. Plaster cracks if you drive screws carelessly: drill a pilot hole, use fixings made for plaster, and fix into the casing or the framing behind it. A deep casing is good news for an inside mount; measure its depth before you choose a louver size.

How to install

Replacement windows

47% of homes went up between 1950 and 1979, and most of them have had their original windows replaced since. A replacement window often sits further into or out of the wall than the old one, so the depth you have for an inside mount may differ from window to window in the same house. Measure every opening rather than copying one.

Choosing a louver size

Whole-house orders

With 67% of homes detached, most orders here cover a whole house: bedrooms, a patio door, perhaps a bay. Put every window in one list in the designer so the louver size and colour match from the street, and if you have an HOA, send it the drawings before you order.

Bay window shutters

Dry summers, wet winters

Barely any of the year's precipitation falls in June, July and August; most comes in the cool months. Wood takes on moisture in the wet season and gives it back in the dry one, so expect the panels to feel slightly tighter in winter than in summer. Fit them in the season you're in, and leave the hinge screws a quarter turn from tight until they've been through both.