THE chairman of the Sports Development Board, David Gledhill, yesterday called on all national sports associations to take up the offer of moving to Sports House, saying it would be absurd if the purpose-built facilities were not used to the full. Addressing a Sports House presentation at the Science Museum, Gledhill said there was no compulsion for associations to move to Sports House - part of the Royal Hongkong Jockey Club's redevelopment of the Hongkong Stadium in So Kon Po. But he added that time was running out and the SDB had set a February 26 deadline for the associations to make up their minds. ''We are not forcing anybody to move. What we have here are free facilities and there's a guarantee for them to stay there permanently,'' said Gledhill. The SDB chairman said it would be absurd for the facilities to remain idle when only $1 was asked for annual rental. If all 24 sports association tenants at Queen Elizabeth Stadium take up the offer, $3.5 million would be saved in rent and made availableto plough back into the respective sports. Explaining the deadline, Gledhill said the architects must have their final blueprint for construction as any delay could add to costs. In all, there 52 national sports associations which are affiliated with the Amateur Sports Federation and Olympic Committee. So far, 14 sports association have indicated that they don't want to make the move. These include the associations who have their own offices elsewhere or don't have full-time staff namely hockey, horse society, ice hockey, parachute, post-secondary colleges athletics, rowing, the sports association for the mentally handicapped, the sports association for the physically disabled, softball and squash. Four sports associations who are currently being housed at the Queen Elizabeth Stadium, namely volleyball, taekwondo, swimming and tenpin bowling, have indicated that they won't move.