Project Details


Craven Lodge Residential and Offices


Harrogate, England


October 2023

About The Project

Part of the Harrogate conservation area, Victoria Avenue is wonderful example of a tree-lined, Victorian avenue, with equally impressive architecture of the era, and home to many people of note over the years.

Sitting in a position of prominence on the avenue, Craven Lodge is an imposing, double-fronted dwelling, and was the first Victorian villa to be built on the site. After many years of disuse, a full renovation is taking place to change the building from its recent multiple office use, into a mix of quality offices and luxury apartments.

In order to increase the green credentials, and to add a further degree of privacy to the frontage, a 22-metre trench was planned in order to provide adequate shared rooting volume for the four, 3-metre-high Hornbeam ‘Frans Fontaine’ trees. These stunning trees retain their columnar shape into maturity, and are an excellent choice to provide a classic architectural shape and excellent colour, especially in the Autumn.

The new trees were placed to break up, and sit between parking spots at the front of the building, so a solution was required to enable the cars to be parked, without any risk of their weight compacting the soil in the tree pits.

What was done

Callum Bain-Mackay of Grant Horticulture approached Green-tech for suggestions on the best way to get the optimal rooting volume for the tree pits, within the tight space constraints of the property. The original drawing from landscape architects Smeeden Foreman showed three trees, but it was decided that the length of the frontage could stand four.

The original thought was to use Green-tech’s sandwich-construction TreeRaft®, but the lack of space, made this unviable. So, Green-tech suggested the new TreeParker® Urban Tree Pit System, which would involve less digging out laterally of the existing made ground.

The initial plan was for separate tree pits for each tree, but on looking at the landscape drawing, Green-tech suggested one long trench. This offered two advantages over individual tree pits, especially as there were now four instead of the original three. Firstly, trees are quite happy to share space, so if we can provide them with one larger pit to share, the roots can borrow space from the other trees, in effect gaining more rooting volume. Secondly, by only excavating one trench, you can save time and labour costs over four individual pits.

The new TreeParker® system comprises rigid, modular units made from reinforced, recycled polypropylene. These units do a vital job in enabling the ground above a tree pit to be trafficked, supporting the paving above (up to 56t/m2), whilst at the same time protecting the soil below from compaction. This means that rather than having to use a fast draining and low organic structural tree soil, we can use our specially blended, GreenTree GeoCell topsoil, that is both friable and organic, ideal for successful tree establishment.

The TreeParker® units, although highly rigid, still provide 95% of their volume for rooting space. The heavy-duty, reinforced legs are available in various heights from the factory; 400, 600, 800mm and 1, 1.2, 1.5m. This gives a previously unheard-of flexibility with depth options. It also enables the units, by having legs rather than side walls, to easily straddle, or work around service pipes and lines.

This was the first time that Callum and his team had installed the system, and although TreeParker® has been used in high-profile projects throughout mainland Europe for several years, Grant Horticulture are the first company in the UK to install the system with Green-tech since its launch in March at Future Build. With this in mind, Green-tech was on hand to advise on the installation process, and even get hands on helping!

Callum, Grant Horticulture’s Lead Designer, and the team were very impressed with the speed and ease with which the units went in. Even when several unexpected service pipes were discovered running through the trench this didn’t pose a problem; the individual support legs of the units simply straddled the pipes, providing an easy workaround. The adjustability of the units is further enhanced by being able to be linked directly, or with 50 or 75mm spacers, or even stand alone.

Green-tech also supplied 40 tonnes of GeoCell topsoil and GreenTree subsoil direct from the soil bays at GT HQ, along with Mona Relief irrigation pipes and tree anchors.

We have worked with Green-tech for several years, mainly for supplies, not anything quite as big as this. They were happy to spend time explaining the system, bringing units over for us to see first-hand, providing technical drawings, and generally being supportive, with nothing being too much trouble. TreeParker® is definitely something we will use for future tree pits.

Callum Bain-Mackay – Senior Garden Designer – Grant Horticulture

TreeParker® is a really exciting development for the urban landscape market, and it was fantastic to have the first UK mainland job happen right on our doorstep here in Harrogate. It was a pleasure to work with a local landscape company such as Grant Horticulture, and a great bonus to be able to be involved with the installation. We’re looking forward to seeing the trees flourishing in the final refurbished property.

Alasdair Innes – Specification Advisor – Green-tech Specifier Advisor