The Norfolk Boreas Offshore Wind Farm Order 2021

Detailed design parameters onshore

16.—(1) The total number of converter buildings for the onshore project substation must not exceed two.

(2) Construction works for the converter buildings referred to in paragraph (1) must not commence until details of the layout, scale and external appearance of the same have been submitted to and approved by the relevant planning authority.

(3) The onshore project substation must be constructed in accordance with the details approved by the relevant planning authority.

(4) Any details provided by the undertaker pursuant to paragraph (2) must:

(a) accord with the design and access statement;

(b) in the event of Scenario 1, be supported by a statement illustrating how the details submitted accord with the principles of the OPS Masterplan and have been informed by a strategic approach to mitigate cumulative impacts arising from the onshore project substation and the Norfolk Vanguard Onshore Project Substation;

(c) have been subject to an early independent design review which must consider whether the requirements of sub-paragraphs (a) and (b) have been satisfied and make recommendations for design improvements if not; and

(d) be within the Order limits.

(5) Buildings (including the converter buildings) comprised in Work No. 8A must not exceed a height of 19 metres above existing ground level and external electrical equipment comprised in Work No. 8A must not exceed a height of 25 metres above existing ground level.

(6) The total footprint of each converter building must not exceed 110 metres by 70 metres.

(7) The fenced compound area (excluding its accesses) for the onshore project substation comprised in Work No. 8A must not exceed 250 metres by 300 metres.

(8) For the purposes of paragraph (5) of this requirement,

(a) In the event of scenario 1, ‘existing ground level’ means 73 metres above ordnance datum; and

(b) In the event of scenario 2, ‘existing ground level’ means 72 metres above ordnance datum.

(9) The external electrical equipment comprised in Work No. 10A must not exceed a height of 15 metres above existing ground level.

(10) For the purposes of paragraph (9) of this requirement, ‘existing ground level’ means 69 metres above ordnance datum.

(11) The fenced compound area (excluding its accesses) for the extension to the Necton National Grid substation comprised in Work No. 10A must not exceed 135 metres by 150 metres in the event of scenario 1, or exceed 200 metres by 150 metres in the event of scenario 2.

(12) In the event of scenario 2:

(a) construction works for the permanent replacement overhead pylons comprised in Work No. 11A must not commence until details of the same have been submitted to and approved by the relevant planning authority;

(b) the permanent replacement overhead line pylon works comprised in Work No. 11A must be constructed in accordance with the details approved by the relevant planning authority;

(c) the permanent replacement overhead line pylons comprised in Work No. 11A must not exceed a height of 55 metres above existing ground level, and for the purposes of this sub-paragraph ‘existing ground level’ means between 66 and 69 metres above ordnance datum in respect of the eastern pylon identified on work plan 41b of 42 with the letter ‘E’ and between 68 and 70 metres above ordnance datum in respect of the western pylon identified on work plan 41b of 42 with the letter ‘W’; and

(d) the total footprint of each permanent replacement overhead line pylon comprised in Work No. 11A must not exceed 25 metres by 25 metres.

(13) In the event of scenario 2, trenchless installation techniques must be used for the purposes of passing under—

(a) the River Wensum (Work No. 7);

(b) King’s Beck (Work No. 5);

(c) Wendling Beck (Work No. 7);

(d) River Bure (Work No. 6);

(e) North Walsham and Dilham Canal (Work No. 5);

(f) the Witton Hall Plantation along Old Hall Road (Work No. 5);

(g) the Wendling Carr County Wildlife Site (Work No. 7);

(h) Little Wood County Wildlife Site (Work No. 7);

(i) land south of the Dillington Carr County Wildlife Site (Work No. 7);

(j) Kerdiston proposed County Wildlife Site (Work No. 6);

(k) Marriott’s Way County Wildlife Site/ Public Right of Way (Work No. 6);

(l) Paston Way and Knapton Cutting County Wildlife Site (Work No. 5);

(m) Norfolk Coast Path (Work No. 4C);

(n) Norwich to Cromer railway line at north Walsham (Work No. 5);

(o) Wymondham to North Elmham Railway line at Dereham (Work No. 7);

(p) A47 Road (Work No. 7);

(q) A140 Road (Work No. 6);

(r) A149 Road (Work No. 5);

(s) A1067 Road (Work No. 7); and

(t) B1149 (Work No. 6).

(14) The number of underground cable ducts to be installed at the landfall must not exceed two.

(15) The footprint of temporary works areas must not exceed the following parameters:

Temporary Work Area	Maximum footprint (m2)
Mobilisation areas	10,000 m2 for each mobilisation area
Trenchless crossing compounds (Scenario 2 only)	7,500m2 at each drill entry site and 5,000m2 at each drill exit site
Temporary landfall compounds at Work No. 4C (up to two)	3,000 m2 for each compound
Temporary construction compound associated with Work No. 8A and 8B.	20,000 m2