Some important considerations with respect to the condition to construct to British Standards
These paragraphs are taken from BS5709:2006
HA1980 s146 Duty to maintain stiles etc. on footpaths and bridleways.E+W
(1)Any stile, gate or other similar structure across a footpath or bridleway shall be maintained by the owner of the land in a safe condition, and to the standard of repair required to prevent unreasonable interference with the rights of the persons using the footpath or bridleway
HA1980 s147 Power to authorise erection of stiles etc. on footpath or bridleway.E+W
(1)The following provisions of this section apply where the owner, lessee or occupier of agricultural land, or of land which is being brought into use for agriculture, represents to a competent authority, as respects a footpath or bridleway that crosses the land, that for securing that the use, or any particular use, of the land for agriculture shall be efficiently carried on, it is expedient that stiles, gates or other works for preventing the ingress or egress of animals should be erected on the path or way.
For the purposes of this section the following are competent authorities—
(a)in the case of a footpath or bridleway which is for the time being maintained by a [F380non-metropolitan] district council by virtue of section 42 or 50 above, that council and also the highway authority, and
(b)in the case of any other footpath or bridleway, the highway authority.
(2)Where such a representation is made the authority to whom it is made may, subject to such conditions as they may impose for maintenance and for enabling the right of way to be exercised without undue inconvenience to the public, authorise the erection of the stiles, gates or other works.
[F381(2A)In exercising their powers under subsection (2) above a competent authority shall have regard to the needs of persons with mobility problems.
(2B)The Secretary of State may issue guidance to competent authorities as to matters to be taken into account for the purposes of subsection (2) above; and in exercising their powers under subsection (2) above competent authorities shall have regard to any such guidance issued to them.]
(3)Where an authorisation in respect of a footpath or bridleway is granted under this section the public right of way is to be deemed to be subject to a condition that the stiles, gates or works may be erected and maintained in accordance with the authorisation and so long as the conditions attached to it are complied with.
(4)For the purposes of section 143 above, any stile, gate or works erected in pursuance of an authorisation under this section is to be deemed to be erected under this section only if the provisions of the authorisation and any conditions attached to it are complied with.
(5)In this section references to agricultural land and to land being brought into use for agriculture include references to land used or, as the case may be, land being brought into use, for forestry [F382or for the breeding or keeping of horses.]
(6)Nothing in this section prejudices any limitation or condition having effect apart from this section.
Please note that it is unclear whether conservation grazing is the same as agricultural use see ROWLR s4.1:Obstructions p17-21 and p31-38
Now the Equality Act 2010
3.1.1 Rights of Way users
Structures shall be assessed to ensure that they are suitable, as a minimum, for the following
legitimate path users with respect to categories of rights of way (see Highways Act 1980 
and Countryside Act 1968 ):
1) walkers (pedestrians);
2) wheelchair users;
3) walkers with dogs under control;
4) walkers with prams/pushchairs;
1) all footpath users;
2) horse riders;
4) persons leading horses;
Please note item 4) does not say that persons leading horses have to be walking. Ie, structures should allow for mounted persons leading horses too?
HA1980 s130 Protection of public rights.E+W
(1)It is the duty of the highway authority to assert and protect the rights of the public to the use and enjoyment of any highway for which they are the highway authority, including any roadside waste which forms part of it.