New Swift boxes at Lowgill

In 2013 we reported on developments at Tanya & Edmund Hoare's Lowgill house. Over the years, this has developed into 4 Schwegler 25s Swift bricks, 6 Zeist boxes, and most notable of all, 10 custom internal spaces in the eaves that are viewable from the bathroom and bedrooms! This post describes a major extension of the nest sites available with internal boxes in the gable.

by

Tanya & Edmund Hoare

We have swifts nesting in our eaves at Lowgill, Cumbria and four pairs in Schwegler 25s bricks in the gable that we installed 7 years ago. Those, in the gable end, were all occupied in the first year and have always been by far the most popular place with bangers. So last winter we decided to create a further 12 sites in the gable, using the Cambridge System similar to that at Fulbourn, with entrance pieces linked to internal boxes in the loft by 4” drainpipes.

Demolition of the 2' thick chimney breast

The gable wall consisted of a redundant chimney breast 2ft thick. As Swifts may be less willing to navigate a pipe 24" long, we decided to rebuild the gable with a narrower wall incorporating 12 pipes 12 inches long.

A platform of mortar was put into the pipes so that the swifts could get a grip when they crawl along.                

Former with cast entrance piece

Custom made entrance pieces were made by making a mould and using formers kindly made by Dick. They were coloured to match the sandstone walls. An attraction call system was installed with the loudspeaker in the apex of the gable.

Wooden nest boxes were fitted in the loft, each with a camera. Shelves were put up on the inner wall for the boxes to rest on so that they could easily be removed if necessary.

While the house was scaffolded we decided to also install another 2 Schwegler 25s at the edge of the gable where we couldn’t use the pipe system.

The end result is aesthetically more pleasing than using commercial bricks. 

Already in the first season we’ve had success, with both the new Schweglers occupied by roosting pairs. Bangers have approached the new holes although so far none have gone in, but fingers crossed for next year.

Rebuilding the wall 12" thick with embedded pipes and entrance pieces

The completed wall with 12 entrance pipes

Shelving support 12 nest boxes behind each pipe.

The finished wall on the outside showing the new Schwegler 25S boxes lower left and lower right, the original 4 Schwegler 25S's and then the 12 new Cambridge System entrances. Although the half-brick entrance pieces are normally used in a brick wall, they don't look at all out of place in a stone wall.

#Cambridge

Entrances made by cutting bricks

We no longer recommend that people make an entrance to an internal nest box by cutting bricks, unless you know what you are doing. This is because of a number of experiences of getting the wrong size, both too small and too big. Here is an example of how to do it properly.

The tolerences for the smaller dimension of a Swift entrance are rather tight. Too big will let Starlings in and too small will make it difficult for Swifts. The longer dimension of the entrance is not critical. Perhaps a minimum of 50mm, often set at 65mm and bigger than this is OK.

Starlings can squeeze into 30mm. The smallest dimension that a Swift can squeeze into is ~25mm. So we recommend 28mm ± 1mm

In Kev Gray's own words:

"... I ended up cutting a very accurate slot to your dimensions into the top face of a matching house brick. I used a stone cutter in my 9 inch grinder, it didn't take many minutes, I bonded a slate lid over the top of the cut out and fitted the whole brick. If one uses mortar to fashion the 4th side of the entrance, there is much scope for getting it wrong. Prefabricating the entrance ensures the correct size.

First we cut the brick out of the wall, we used a battery powered masonry drill and bit and just drilled a series of holes all the way around the brick and it came out quite easily.

The hole was then tidied up with a bolster chisel and the swift brick fitted.

A long masonry bit was positioned in the centre of the Swift slot from the outside of the wall and guide hole was then drilled through the inner wall, the wall on the other side of the cavity, this is usually breeze block and drills very easily.

From inside the loft.

The guide hole previously drilled in the breeze block is then used to guide a large diameter masonry hole cutter, if it's breeze block it cuts quite easily, if you don't have access to a hole cutter you could use drill a series of small holes drilled in a circle and chisel the middle out.

When the hole is finished measure from the internal face of the breeze block back to the inside face of the Swift brick to establish the length of soil pipe required.

The pipe is just ordinary 110mm soil pipe, anything similar would do, you can get it from most DIY stores., I can be cut with a hand saw and positioned into the hole so that it butts up to the new swift brick, take care if the mortar is still soft as you may dislodge the swift brick, it's better to leave it time to set. When the pipe is in position use some mortar to fill in any gaps and holes that may be in the swift brick to make a nice smooth passage without any sharp edges. Also it's a good idea to put a bed of mortar along the bottom run of the soil pipe as this will help the Swifts have a bit more grip onto what would otherwise be a very slippery surface. In fact it's a good idea to give the inside of the soil pipe a good roughing out with some course sandpaper before putting it into position as this will help the mortar stick.

As mentioned earlier, I made up a couple of boxes from some spare 18mm chipboard floorboard because that what I had handy, but you could use something much thinner maybe some plywood. Bill Murrells recommend internal dimensions of W 200 x L 300 x H 150 for the box and that is what I went with.

Removing a brick

Components of the entrance brick, before cutting

Relative positioning of soil pipe and entrance brick

The completed entrance

A view from the inside

Swift boxes at the David Attenborough Building

The David Attenborough Building in Cambridge houses conservation practitioners and academics, who are working together Cambridge Conservation Initiative (CCI).

"The David Attenborough Building will act as a collaborative hub for the conservation community within Cambridge and beyond - Mike Rands"

It had always been the ambition of the executive director, Mike Rands, to have breeding Swifts, so AfS was invited to see what might be possible. As all the building work had been finished, this was a retrofit situation on a very smart building that we would not want to compromise in any way.

Two opportunities presented themselves: boxes installed at the top of one of the towers and boxes on the parapets. As the former would be less visually intrusive, Mike suggested we go for the towers.

The tops of the towers are octagonal with vertical bars containing 4 of the sides. The bars are 50mm wide and spaced 50mm apart (see pictures below).

John Stimpson supplied 8 Model 30 nest boxes, but with no entrance in the front. This was a suitable choice as the top of the tower is exposed to the sky, so the boxes may receive both rain and sun.

For the Swifts to gain access to boxes inside the bars, it would require tunnels about 15cm long to the outside.

We have some anecdotal evidence that Swifts will not negotiate a small tunnel of this length (e.g. here). Thus we made tunnels with inside dimensions 43mm wide x 65mm high.

A D-shaped hole was cut in the back and tunnels fashioned out of roofing plastic glued in place.

Roofing plastic put into boiling water is easy to shape around, in this case, an empty can of hairspray.

Rubber strips provided separation and friction between the boxes and the metal bars.

The tunnels could also provide access for Starlings, so the top part of the tunnel is blocked on the inside face of the box. This should leave enough space for a Swift to enter, but not a Starling. One of the concerns was not to have bird droppings down the building.

The brackets, made of stainless stud and aluminium bars, were made by Dexter Bullman of Landbeach. They were painted to match the vertical bars.

A Cheny Heny MP3 player was installed driving 2 tweeters facing outwards below 2 of the tunnels. We gave some thought to the possibility of Swifts coming through the bars, but as the space is open to the sky, they should be able to get away.

The pictures below illustrate what was achieved:

4 tunnels outside the SW side and 4 boxes inside the SE side

Close up of the 4 tunnels on the SW side

Installation team: Bill Murrells, Elizabeth Allen, Collaborations & Communications Manager,
Dexter Bullman and Mike Rands, Executive Director.
Dick Newell took the picture

Another nice result of the Cambridge System

Two things are new about this project: firstly it is an example using CJ WoodStone boxes inside, secondly it is one of the first projects implemented by someone other than AfS.

[Update summer 2017: From 17th June Swifts have found the boxes and stayed for extended periods. Good prospects for 2018]

Jan Stannard's Victorian gable in Maidenhead is just one brick thick, so although there was no access inside the gable, it was practical to tackle this project wholly from the outside.

The project used 2 WoodStone build-in boxes and 2 homemade entrance pieces:

2 WoodStone build-in boxes and 2 homemade entrance pieces

Boxes and entrances in place

It was necessary to remove 2 courses of brickwork to install the boxes. This is rather more intrusive than one normally likes, but an excellent result has been achieved

The half bricks have been placed nicely to avoid aligned vertical bonds.

The homemade entrance pieces were cast using white cement and were then stained using Ecos Paints. One has to agree, the colour match is very good.

The nest boxes are the WoodStone® Build-in Hidden Swift Box




#cambridge

Internal boxes in Dry Drayton

In 2015, Rowena Baxter described her project to get  Swift boxes installed in Dry Drayton. This has resulted in a total of 8 out of 23 boxes occupied by Swifts in 2016. No Swifts were known to nest in Dry Drayton prior to the start of this project.

Rowena decided to take the plunge and install internal boxes in her gable at roof space level, using what has come to be known as the Cambridge System. Two external boxes under the eaves of the same gable, installed in 2015, housed one pair of Swifts in 2016.

Bill and Dick managed to install 3 half brick inserts and the boxes in one day. There is nothing new here, but we are pleased how it turned out. Technical details are:

The half brick inserts were cast in white concrete, then stained red.

The bricks each side of a vertical bond were reduced by 56mm to make space for the insert.

The nest boxes are made of treated external plywood: a simple "shoebox" with internal dimensions W 25cm x L 20cm x H 15cm. Flanges above and below the front of the box are screwed directly into the blocks, which are made of soft vermiculite. The top screws were angled downwards as this is more secure.

A simple hinged door on the back allows for inspection and maintenance.

The PVC pipe has an external diameter of 107mm. The pictures below show how the pipe is trimmed to span the cavity. A slot is cut in the top of the pipe as it is a tight fit. Mortar was placed in the bottom of the pipe to provide traction for the Swifts.

A 107mm diameter core drill was used to make holes through the blocks

Two eaves boxes and 3 new internal boxes
The external box on the right had breeding Swifts in 2016. Photo Clive Cooper

Close up of one of 3 entrances. Photo Clive Cooper

Internal box, showing hinged door and simple catch. Photo Clive Cooper

Components of the Cambridge System: entrance piece, pipe, nest box and concave.

Components in context

UPDATE July 2017: there are now 3 pairs in the 4-box cabinet, 1 pair in the eaves boxes and 3 pairs in the internal boxes, of which 2 are sitting on eggs. The neighbours down the street have a further 8 pairs.

One of 3 pairs in the internal boxes - photo Clive Cooper

#inserts #cambridge

The Manthorpe Swift Brick back story

The Manthorpe Swift Brick has been announced and is now in full production. It is well described on Manthorpe's website, so we thought it worth describing how it came about.

The origins of the concept go back to 2014 when Judith Wakelam wished to add more nesting places on the gable end of her bungalow after having success with an external nest box. Bill Murrells came up with the idea of making a Swift entrance piece to replace a half brick in the wall. 3 such entrances were installed, and since then Swifts have bred in one of them and have explored the other 2.

Bill's entrance pieces were fabricated out of pieces of clay air brick liner; we have implemented one other project using this idea. Since then we have found it simpler to cast the entrance pieces using a simple mould.  A further 7 projects have been completed using cast entrance pieces, mostly half-brick sized and one with a whole brick sized entrance.

Extensions of the idea by casting entrances in situ have also been completed, one such project in Spain resulting in 100 nest places in a castle.

There are case studies of all these projects here

In all cases, the final result is attractive and neat, giving secure accommodation for Swifts. The approach has been labelled "The Cambridge System". [We hope that the Cambridge System itself will be commercialised soon].

At this point, on a visit to Cambridge by John Day of the RSPB he thought that the concept might be of interest to Barratt Homes. RSPB and Barratt have a partnership agreement. In October 2015, a meeting was arranged with Technical and Design Director Michael Finn. Michael carefully assessed what we showed him, and commented that when they put accessories, such as ventilation grills, in walls they use injection moulded products and he asked whether it would be possible to have an injection moulded Swift box.

It so happens that, in 2013, we had looked at the potential of an injection moulded Swift box so we produced a computer model of what we thought would be a simple, cheap and unobtrusive injection moulded Swift box.

I dug this out and sent it off where it ended up with the design engineers at Manthorpe Building Products, who immediately understood what was required and produced a first design, including their own innovative ideas.

On a visit to Manthorpe's offices in early December 2015, Paul Stephen, RSPB, and I were shown a complete 3D-printed prototype. The level of thought put into the detail was impressive.

A few iterations later and the product has now been launched and the first examples have already been installed.

Injection moulds are expensive, but the per unit costs are low. So it took a fair bit of courage to commit to an untried and untested design. There would have been no other way of exploring this approach.

This project would not have happened without the partnership between Barratt Homes and RSPB. You can read the RSPB press release.

We look forward to hearing about the first occupants of these revolutionary new Swift boxes.

Entrances cast in situ

When Barbara Wager, of Thorpe in Derbyshire, contacted us about how to provide Swift accommodation in a stone wall, we discussed various ideas, ending up with making entrances by casting them in situ.

This is a small-scale rerun of the Alcázar of Segovia project, where we, AfS provided formers, and the rest was done on site. In this case, the wall is 2 feet thick. The entrance leads to a natural cavity in the stonework, without any need for a nest box. The cavity is sealed with a board.

These pictures explain exactly how it was done:

2 formers

2 formers embedded in mortar

With formers removed, 2 entrance holes

A view from inside the building, with former still in place

2 neat entrances in the gable

#inserts
#Derby

New Swift nest sites in the Alcázar of Segovia

When we met Javier Saez Frayssinet in Szczecin, we discussed an idea of how to transform irregular holes in walls into entrances suitable for Swifts. We, AfS, had developed a method suitable for casting entrances in situ. The result of this conversation is most gratifying, with 60 new nest sites, so far, being incorporated in the walls of the castle, it may well end up with over 100 new nest sites.

The Alcázar of Segovia. Photo Wikipedia

The Alcázar of Segovia is spectacular (see Wikipedia), and a wonderful setting for a Swift colony. There were many holes in the walls with the potential for turning them into Swift nest sites. Javier took our idea and used it innovatively to fashion attractive entrances in the walls of the castle.  

The method uses a 'former', an object the same size and shape as a Swift entrance.

2 formers

Inside each entrance is a space at least 15cm x 30cm.

The idea is a development of the Cambridge System, but instead of pre-casting entrance pieces, entrances are created in situ in the wall using the formers.

In this project, pieces of terracotta have been used, allowing the formers to be redeployed before the mortar has fully set.

The pictures below show the results.

An entrance fashioned out of terracotta, with former still in place

A finished entrance

An entrance cast around the former

Some of the new entrances in the wall on the right

#inserts
#Derby

Internal Swift boxes in a difficult situation

We have had external Swift boxes on our 17th century house since 2004, with 9 pairs in 2015. Being a listed building, the scope for internal boxes is limited, with just one possible location at the top of a gable end which was built about 50 years ago to replace what was a wooden dairy. 

by Dick Newell

There is no possibility of access to the roof space behind the gable. However a test hole showed that there was a cavity 100mm wide behind Dutch bricks 110mm wide. So, I reckoned we could fit a nest box spanning the cavity and 8cm of the outer wall, giving a floor area of 18cm by 25cm - big enough for a Swift box.

The wall is constructed of nicely selected reclaimed bricks of many textures and colours, so the challenge was how to produce forged brick entrance pieces which look the same.

I eventually took the plunge and we removed one brick from high up in the gable and cast a whole brick insert, 3cm thick out of white cement. A nest box was assembled in the cavity, ship-in-bottle fashion, out of cement fibre-board and glue. This is another variant of the Cambridge Swift Box System.

The internal length of the nesting chamber is 30cm in the cavity and 25cm in the outer wall. The head room is 14cm in the cavity and 7cm in the outer wall.

The first box we deemed a success, so 2 more bricks were removed and 2 more inserts were used, one made of a mixture of white and grey cement and the other the same, coated in crushed red-brick .

The 3 inserts looked a little different from the bricks around them, but with a judicious use of a used tea bag, coffee spread with a finger, and cement powder dotted liberally over the surface, a very good match was achieved.

If the Swifts like these first 3 nest boxes, then there is scope for at least another 2 boxes.

Much of the credit for this goes to Bill Murrells and his remarkable brick laying skills.

Old Beach Farm, Landbeach with 3 internal nestboxes at the top of the near gable

Close up of 3 entrances with forged bricks coloured to match the existing brickwork.
Note the tweeter below the alarm box

3 cast brick entrance inserts.

Components of the fibre-board box before assembly in the wall.
The overall internal length in the cavity is 30cm.

The first nest box completed, and the second brick removed ready for assembling the nest box.
The colour of the first box was a little too white, but tea bags and coffee toned it down.

UPDATE July 21st 2016 - the first Swift occupies one of the boxes.  The wire leads to a small tweeter poked in through the entrance:

#inserts
#Cambridge

Some implementations of the Cambridge Swift Box System

The Cambridge Swift Box System is a method of installing internal nest boxes, by replacing a whole brick or half brick with a cast insert containing an entrance hole, with a nest box inside the building.  

We have now installed boxes in 8 houses with pleasing results in all cases (see examples - scroll down to see all examples). It is particularly straightforward in solid walls, at roof space level, where the headers go all of the way through the wall. Such walls typically have soft lime mortar, so removing a header is an easy job. Below are some pictures of the results from 3 such projects. In all cases, the boxes inside the roof space are a simple plywood construction, with a hinged inspection door.

The first example 
This came about when we were walking down Haddenham High Street and we spotted an old unused Zeist Swift box on a gable end. The owner was in the garden, so we engaged in conversation. There were 3 missing bricks in the wall above the Swift box, so we made the obvious suggestion to her, resulting in 3 new nest places for Swifts, instead of the Zeist box.

The original unoccupied Zeist box, exposed to sun and rain,
with 3 bricks missing from the wall

3 entrance pieces inserted

Close up

The second example
This is right next door to the first example, and was the reason we were walking down Haddenham High Street in the first place
[Update 2017: 2 pairs of Swifts have moved into the boxes on the right]

The whole gable end, with 2 sets of 3 entrances

Close up of 3 entrances

The third example
This is an old vicarage in Longstanton.
[Update 2017: the first pair of Swifts has moved in]

6 entrances virtually invisible from a distance

Close up

#inserts
#Cambridge