Solar Panel Installation
in Royston

Royston's defining planning quirk is a border. The Hertfordshire and Cambridgeshire county line ran through the middle of the town until an 1896 change placed the whole town in Hertfordshire, and the SG8 postcode district still reaches across the modern boundary — which is why postcode directories disagree about which county Royston is in. The national permitted development rules are identical on both sides, so the rules themselves are not the issue. What differs is which conservation areas and Article 4 directions apply, because those belong to the council the property sits in. North Hertfordshire Council covers the town, but for an address on the fringe the authority should be read off the full postcode before a layout is designed or an application drafted.

The town's conservation area covers the historic core and is long-established: North Hertfordshire Council states the boundaries were drawn up in 1969, and the Historic England record gives the designation date as 6 October 1969. The supporting documents — an assessment of the area's setting, character and appearance, and a townscape analysis with an addendum — were approved on 27 March 2007, and the council publishes the boundary map with an errata sheet, which is worth requesting rather than relying on a screenshot. Being inside the area rarely rules solar out: under paragraph A.1(2)(e) of the amended Part 14 what is withheld is equipment on a wall, a balcony or a roof enclosure fronting a highway, not an array on a roof slope.

Royston has the best modelled solar resource of any town on our map. The European Commission's PVGIS model, run at latitude 52.0479, longitude -0.0206 with the PVGIS-SARAH3 radiation database, a 35-degree pitch and 14% system losses, returns about 1,040 kWh a year per kWp facing due south — ahead of St Albans, Watford and Hemel Hempstead on the same assumptions. East comes out at about 828 kWh and west at about 807 kWh, so roughly 80% and 78% of south. Ten AIKO 485W panels, 4.85 kWp, on a south slope would be modelled at roughly 5,000 kWh a year before shading. July runs at about 127 kWh per kWp against about 34 kWh in December, so the winter figure, not the annual one, is what a battery should be sized against.

The geology under the town is unusual enough to matter for groundwork. Royston sits on Middle Chalk, part of the New Pit Chalk Formation, with only topsoil or loam separating it from the surface — near-surface chalk soft enough that the small historic workings known as bell pits and dene holes were dug into it, and that Royston Cave, a Grade I listed scheduled monument beneath the crossroads of Ermine Street and the Icknield Way, was cut by hand. For a roof-mounted system this is irrelevant. For a ground-mounted array or a long cable run to an outbuilding it is not: shallow chalk changes how foundations are specified and how trenching is dug, and it drains quite differently from the clay soils further south in the county. Flag a ground mount at survey so the groundwork is priced rather than assumed.

The land immediately south-west of the town is protected, which shapes where anything ground-mounted can go. Therfield Heath, known locally as Royston Heath, is both a Site of Special Scientific Interest and a Local Nature Reserve covering 143.3 hectares of chalk escarpment, and it contains scheduled Neolithic and Bronze Age barrows, including Hertfordshire's largest round-barrow group. That is not a planning constraint on a domestic roof in the town, but it does mean any proposal on or adjoining the heath carries designations well beyond ordinary planning, and that the open chalk grassland to the south is not developable land in the way an inexperienced site appraisal might assume.