Planning summer shade: test the window at the troublesome hour

Write a brief for one window

Choose the room that concerns you most. For an existing home, record when direct sun reaches the glass and what bothers you inside. Separate feeling hot from struggling with glare: both matter, but they are different observations. Add whether the windows and blinds were open or closed.

For a proposed home, mark the relevant window and the hours you expect to use the room. Ask the designer to test those conditions. A shadow study can help explain direct sun, but it does not by itself predict the room's temperature.

• Which window is receiving the sun?
• Is the concern heat, glare, or both?
• What daylight or view do you want to keep?

Follow the shadow onto the glass

MBIE's passive cooling guidance explains that exterior shading can stop sun reaching windows before it enters the home. It also recommends considering summer cooling alongside winter warmth and ventilation. I would therefore ask where the proposed shade lands on the window, rather than judge it only by the shaded area on the deck.

BRANZ's Level guidance distinguishes high summer sun on north-facing windows from lower morning and afternoon sun on east and west faces. The latter is harder to shade. A horizontal overhang that helps at midday may leave a different problem later in the day.

In a hypothetical west-facing living room, I would compare the proposed overhead cover with an adjustable screen at the relevant afternoon hours. Ask for the same viewpoints and dates in each option, with the actual window height and surrounding obstructions included. Then repeat the comparison in winter.

• How much of the glass remains exposed at the hour we care about?
• Does the screen interrupt the outlook from the sofa?
• What winter sun or daylight would the fixed option remove?

Give adjustable shade an everyday routine

An adjustable system needs a plan for how it will be used. I would ask who operates it, where the control is, and what position it should be left in when everyone goes out. If your chosen solution depends on someone being home before the afternoon sun arrives, make that assumption visible.

Level notes that awnings may be unsuitable in windy locations and require maintenance. Ask the supplier about the exact product's operating limits, retraction requirements and controls. If it must be retracted during the conditions you are trying to manage, discuss what the room relies on then.

For sliding or hinged screens, have the designer show both the working position and where they park. Check doors, opening windows, outdoor furniture and access for cleaning in both arrangements.

Keep the outdoor structure and indoor comfort connected

The Prior House project page includes a timber pergola beside the outdoor living area. It is a useful reference for discussing how an external structure sits alongside a home. The photographs are not evidence that the same arrangement will shade your windows at the times you need.

I would put the proposed structure, glazing and furniture on the same drawing. Ask the team to resolve supports, attachments, weather exposure and any consent requirements before treating the shade as a later accessory. If overheating remains uncertain, ask whether a thermal assessment is needed to compare the complete room design.

Bring the hour that needs fixing

Bring a marked plan and a few dated observations to a consultation. We can discuss which windows need closer attention and what the design team should test before you choose an awning, screen or permanent cover.