Impluvium — Concrete pools for the eastern foothills

This is the shell the week before the first fill, straight down at four in the afternoon. The step is forty-five centimetres deep and the far end a little under two metres. The water in it is worked out here: how far the light travels, down to the floor and back, through that much water, and what the floor is made of. The shadows are four o’clock’s; the light and the sky in the water follow the hour you choose. Drag a hand through it and the floor bends under the ripples.

Drawn with the house, not dropped into the lawn

We start where you’ll sit.

Before we draw a pool we walk the garden with you at the time of day you’ll use it most. Which window looks onto the water at four o’clock. Where the olive throws its shade in February, and where it drops its fruit in autumn. How far you carry a towel from the back door, and whether that path is paving or lawn. Where the step goes, so the afternoon sun reaches it first and the first swim of spring starts somewhere warm.

Foothill blocks fall away from the house, so a pool is often cut into the slope and built up on the low side. That makes its far edge one long level line against the fall of the garden, and it decides where the deep end goes and how much the terrace has to hold back. We draw the shape, the depth and the stone with the house and the garden, then one crew takes it from the dig to the first fill, one pool at a time.

where the afternoon shade falls
the depth you can stand in
what you see from the kitchen

At water height across a still pool to its limestone coping, with olive trees and the dry foothills beyond. — At water height, late in the day. The coping is a honed limestone with a rounded edge, wide enough to sit on with your feet in; the render under this water is grey, which turns it a quieter green-blue than white does.

Which shape suits the garden

The garden usually decides: the long side of the block, the old trees, the view, and where the afternoon sun lands. Choose one and the page takes its edge from it.

A garden free-form for a sloping garden with old trees; the edge goes round the roots, not through them.

About 9 m by 4.2 m, from 0.45 m on the step to 1.9 m at the deep end.

Every pool we build has its fence drawn on the first plan and built with it, as part of the garden rather than around it.

The depth you can stand in

Most afternoons are spent at standing depth, so we give it more of the pool than you’d expect. The deep end isn’t always the far end: on a sloping block it’s often better near the house, where the ground is already low.

sit on the step with a cup of tea 0.45 m
the bench along the side 0.5 m
stand with your shoulders out about 1.2 m
the end you swim to 1.9 m

A garden free-form in long section, 9 m from the step to the far wall. Under the line, the water in the colour it takes at each depth over the floor you chose.

From the dig to the first fill

One crew, in this order, from the first cut to the afternoon the water goes in. The drawing is the pool you chose above, floated in the render you chose.

The dig The garden comes apart for a while. We fence off what we’re keeping and cover the paths.
The steel Tied by hand at every crossing, sitting on chairs off the clay.
Sprayed concrete Sprayed in a single day so the shell is one piece, then kept wet for a week while it sets hard.
The render Floated on by hand. This is the colour you’ll see through the water.
The coping Limestone on a mortar bed, cut around the step, the joints lined up with the house.
The water One crew from the dig to the first fill. We’re there when the water goes in.

Straight down into the dug shell, the steel tied at every crossing over red-brown clay. — The steel, the week after the dig: tied at every crossing and held off the clay on chairs, the step already formed at the near end.

Gloved hands lowering a limestone coping stone onto its mortar bed, a mallet and trowel beside it. — Setting the coping. Each stone goes down on a fresh bed of mortar and is tapped level with the next.

Render, pebble and stone

The floor is most of the colour. Under the same water a pale render sends the light back up and a dark one keeps it, so choose the floor for the water you want to look at, not for the square in your hand.

The coping is a honed limestone with a rounded bullnose, wide enough to sit on with your feet in the water, and cut from the same stone as the terrace so the two read as one.

Squares of white render, grey render and charcoal pebble beside a length of limestone coping, seen from above. — The three floors beside a length of the coping, on the terrace stone they’ll sit in.

white cement and marble sand. A pale floor sends the light back: green-blue at the step, turquoise at the deep end.
the same with grey cement. Cooler, like the gulf in winter.
small dark pebbles set in render and washed back. The floor keeps most of the light, so the water turns to slate and holds the sky.

Each floor under half a metre, a little over a metre and just under two, at four in the afternoon.

Warm enough in April?

A pool in the foothills takes in the sun all day and gives it back to the air all night, faster when the gully wind comes down and faster again with nothing over it. Set the pool you have in mind, and we’ll run a whole year through it, hour by hour.

A pool 8.4 m long, 3.6 m wide and 1.4 m deep on average, in grey render, covered at night, with no heat pump.

Length

Width

Depth on average

Heat pump none 9 kW 13 kW 18 kW

This pool sits above 26° for about 17 weeks, from the fourth week of November to the third week of March. In the middle of April the water is about 21°. With the cover left off, it doesn’t quite reach 26°. Worked out on this page for an illustrative pool and a typical foothills year.

Lit from the deep end

At night the water is lit from the deep end, low, so it glows rather than glares. The light is warm, set in the wall, and switched from inside the house. The terrace lights are drawn with the pool, not after it.

The light at 8:00 PM

see it at four

The pool from the top of the page after dark, its light worked out through the water over the floor you chose.

Tell us about the garden

Where it is, what it gets in the afternoon, and anything that has to stay. The pool you’ve drawn on this page comes with it, so we start from where you’ve got to.