O. P. JAIN, J. This petition, under Article 226 of the Constitution of India, has been filed by seventeen petitioners who (except Nos. 5 and 7) are senior mem bers of the teaching staff of Aligarh Mus lim University. They are allotees of houses constructed by Aligarh Development Authority (hereinafter called ADA) which is respondent No. 1. The ADA advertised a scheme known as Dodpur Mafi Self Financing Scheme for persons belonging to Middle Income Group (MIG) and Higher Income Group (HIG ). The terms and conditions are given in a Book let/brochure which was supplied to the applicants. 2. All the petitioners got themselves registered for MIG Flats. The cost of MIG flat on ground floor and first floor was shown as Rs. 1, 40, 000 and Rs 1, 24, 000 respectively. Initially registration fee of Rs 12, 000 and Rs. 15, 000 for first floor and ground floor respectively was deposited by the petitioners on 16th December, 1985 though some of them joined the scheme at a later date and the registration fee was paid by them later. The remaining amount was to be deposited by the allottees in six quarterly instalments. 3. According to the petitioners, as surance was given to them that the flats will be constructed and possession will be handed-over to them within a period of two years. The demand for first instalment was made by ADA on 16th May, 1987 and it requested the allottees to deposit the first instalment of Rs. 20, 000 by 5th June, 1987. The dates on which different instal ments were paid by different petitioners are given in a Chart which is Annexure RA-1 to the rejoinder-affidavit. 4. In June, 1991 the petitioner Nos. 2, 3 and 4 received notices, copies whereof are appended to the petition as Annexure-10-A, 10-B, 10-C and 10-D, whereby they have been informed of the increase in the initial estimated cost of the construction of the flats and calling upon them to pay the difference between the amount paid and the increased cost. The sum demanded for MIG first floor and MIG ground floor is Rs. 1, 60, 000 and Rs. 1, 81, 000 respective ly. 5. The sum demanded for MIG first floor and MIG ground floor is Rs. 1, 60, 000 and Rs. 1, 81, 000 respective ly. 5. The petitioners have prayed that a writ of certiorari be issued quashing notices Annexure 10-A to Annexure 10-D. They have also prayed for a writ of man damus commanding the respondents to fix the price of the flats as stipulated in the Booklet/brochure supplied to them and to execute the lease-deeds in favour of the petitioners. 6. Counter and rejoinder-affidavits have been exchanged between the parties and we have heard Sri VB. Singh and Sri RS. Baghel learned Counsel appearing for the petitioners and Sri Ramesh Chandra Upadhyay learned Counsel appearing for respondents No. 1 and 2. 7. Relying upon AIR 1989 SC 1076 , Bareilfy Development Authority & Am: v. Ajay Pal Singh & Ors. , Sri Upadhyay has raised a preliminary objection to the main tainability of the petition. He has also drawn attention to the first para of the notices Annexure-10-A to Annexure 10-D which indicates that the impugned in crease was in accordance with the decision between the Representative of the As sociation of the petitioners and the Authorities of the ADA. On this basis it is submitted by Sri Upadhyay that the petitioners are stopped from challenging the increase in the cost of construction. 8. Para 1 of notice Annexure 10-A reads thus:- UPROKTA VISHYAK UPAD-HYAKSH, ALIGARH VISHVA- VIDYALAYA, ALIGARH KE SAMAKSH AAP KE ASSOCIATION KE PRATINID-HI YON KE SAATH HUIVARTA MEN LI YE GAYE NIRNAYA KE ANUSAR 24 BHAVANON KA NIRMAAN LAGAT KO MILAKAR SANSHODHIT RUP SE BHAVANON KI LAGAT MEN NIMNWAT AANSHIK SANSHODHAN KIYA JATA HAL" 9. There is no denial in the petition of the facts mentioned in paral of the notice Annexure 10-A which has been quoted above. 10. In AIR 1989 SC 1076 , Bareilty Development Authority & Anr. Ajay Pal Singh & Ors. , relied upon by Sri Upadhyay, Honble Supreme Court has held thus: "there is a line of decisions where the contract entered into between the State and the persons aggrieved is non-statutory and purely contractual and the rights are covered only by the terms of the contract, no writ or order can be issued under Article 226 of the Constitution of India so as to compel the authorities to remedy a breach of contract pure ad simple: Radhakrish-naagarwalv. State of Bihar, (1977) 3 SCR 249 ; AIR 1977 SC 1496 ;premijbhaiparmarv. Delhi Development Authority, (1980)2 SCR 704 ; AIR 1980sc 738 and D. F. O. v. Biswanath Tea Com pany Ltd. , (1981) 3 SCR 662 ; AIR 1981 SC 1868. In view of the authoritative judicial pronouncements of this Court in the series of cases dealing with the scope of interference of a High Court while exercising its writ jurisdiction under Article 226 of the Constitution of India in cases of non-statutory concluded contracts like the one in hand, we are constrained to hold that the High Court in the present case has gone wrong in its finding that there is arbitrariness and unreasonableness on the part of the appellants herein in increasing the cost of the house/flats and the rate of monthly instalments and giving directions in the writ petitions as prayed for. " 11. Sri VB. Singh, learned Counsel for the petitioners relies on JT1995 (3) SC page 1, Indore Development Authority v. Smt. Sadhanaagarwal& Ors. , in which the Apex Court referred to the case Of Bareilly Development Authority (supra) and D. D. A. v. Pushpendra Kumar Jain, JT 1994 (6) SC 292 and made the following observations in para 9: "although, this Court has from time to time taking the special facts and circumstances of the cases in question has upheld the excess changed by the development authorities, over the cost initially announced as estimated cost, but it should not be understood that this Court has held that such development authorities have absolute right to hike the cost of flats, initially announced as approximate or estimated cost for such flats. It is well known that persons belong ing to Middle and Lower Income Groups, before registering themselves for such flats, have to take their financial capacity into con sideration and in some cases it results into great hardship when the development authorities an nounce as estimated or approximate cost and deliver the same at twice or thrice of the said amount. The final cost should be proportionate to the approximate or estimated cost mentioned in the offers or agreements. The final cost should be proportionate to the approximate or estimated cost mentioned in the offers or agreements. With the high rate of inflation, escalation of the prices of construc tion materials and labour charges, if the scheme is not ready within the time frame, then it is not possible to deliver the flats or houses in question at the cost so announced. It will be advisable that before offering the flats to the public such development authorities should fix the es timated cost of the flats taking into considera tion the escalation of the cost during the period the scheme is to be completed. In the instant case, the estimated cost for the LIG flat was given out at Rs. 45, 000. But by the impugned communication, the appellant informed the respondents that the actual cost of the flat shall be Rs. 1, 16, 000 i. e. the escalation is more than 100%. The High Court was justified in saying that in such circumstances, the Authority owed a duty to explain and to justify the Court, the reasons for such escalation We may add that this does not mean that this does not mean that the high court in such disputes, while exercising the writ jurisdiction, has to examine every detail of the construction with reference to the cost incurred. The High Court has to be satisfied on the material on record that the authority has not acted in an arbitrary or erratic manner. " 12. It will, thus, be seen that the prin ciple Laid down in Bareilfy Development Authority & Anr. v. Ajay Pal Singh and others (supra), has not been changed or departed from in the case of Indore Development Authority v. Smt. Sadhana Agarwal (supra ). Therefore, exceptional cases apart, ordinarily this Court will not interfere in the case of a non- statutory executed contract unless the Court finds that the authority has acted in an arbitrary or erratic manner. 13. We have examined the record from this point of view and we find that under Clause 21 of the Booklet/brochure the cost mentioned was estimated cost which was liable to increase or decrease. The actual cost was to be calculated on completion of the construction and the same was binding on the allottee. 14. The registration was done in December, 1985 and the construction started in 1987 as is evident from An-nexure CA-1. The actual cost was to be calculated on completion of the construction and the same was binding on the allottee. 14. The registration was done in December, 1985 and the construction started in 1987 as is evident from An-nexure CA-1. It appears from para 19 (a) of the rejoinder-affidavit that immediately after the issue of allotment order (An-nexure-6) dated 16th October, 1989, the petitioners took possession of the flats without waiting for the formal delivery of possession though the allotment letter (Annexure-6) specifically mentioned that possession was to be delivered only after the execution of the lease-deed. In this way the petitioners got possession after three and half years of registration. According to the averments made in para 4 of the writ petition, an assurance was given to the petitioners that the construction will be completed within two years. At the bottom of page No. 4 of the Booklet/brochure it is stated that the balance amount was to be paid in six quarterly instalments, i. e. in 18 months. Clause 15 of the Book let/brochure gives on option to the allot tees to apply for refund of the amount with. 15. For this delay of about one and half years the petitioners are also respon sible to some extent. The petitioners themselves have furnished a Chart, An-nexure RA-1, which shows that petitioner No. 1 committed default in payment of installment Nos. 1, 3 and 5. The petitioners Nos. 4, 5, 8 and 9 also committed some default. Petitioners No. 1 was informed by Annexure-CA-3 that the delay in payment of instilments is obstructing the progress of the construction work. 16. In para 14 of the rejoinder-af fidavit the petitioners themselves have given the reasons for the delay in the con struction and have stated that the con struction work had stopped because of the fact that the contractors had refused to continue to work since the Vice-Chairman of the ADA, Smt. Prasad, had imposed some fine on three contractors because the contractors had used sub-standard material in the construction work. It is further stated in para 9 of the rejoinder-af fidavit that the Junior Engineer-in- charge of the construction work was also suspended by the Vice-Chairman. 17. Thus, we find that there was no willful default or negligence on the part of ADA. A Semi-Government Organisation has to follow certain procedures like invit ing tenders etc. It is further stated in para 9 of the rejoinder-af fidavit that the Junior Engineer-in- charge of the construction work was also suspended by the Vice-Chairman. 17. Thus, we find that there was no willful default or negligence on the part of ADA. A Semi-Government Organisation has to follow certain procedures like invit ing tenders etc. It cannot remove a eon-tractor or a Junior Engineer without ob serving the principles of natural justice There is some built-in delay in official procedure applicable to an organisation like ADA Therefore, in our opinion the reasons for the delay of about one and half years can be ascertained from the material placed before us and under the cir cumstances noted above, the delay stands explained. 18. Escalation of cost by 30% in a period of three and half years from the date of registration cannot be said to be unusual. Moreover, it has been stated in the supplementary affidavit sworn by Sri Umesh Shukla, Accountant of ADA that interest if possession in not handed-over the enhanced price demanded by the ADA within a year from the registration. This from the petitioners is due to the enhance ment of the cost-price of the flats and also due to enhancement of compensation of the land under the provisions of the Land option was petitioners. Not exercised by the jtendra Pal Singh v. The Chairman & Managing Director Acquisition Act. A copy of the affidavit of Sri Umesh Shukla was sought to be served on the learned Counsel for the petitioners, but he declined to accept it and, therefore, a copy of this affidavit was served on petitioner No. 1 by registered post. 19. After a careful examination of the material placed on record, we come to the conclusion that the delay and consequent escalation of cost of construction is not unusually high and partly the petitioners are also responsible for the same. We are satisfied that the ADA has not acted in an arbitrary or erratic manner. 20. In view of the above discussion, we find no force in this writ petition which is dismissed summarily. Under the cir cumstances of the case, parties will bear their own costs. Writ Petition dismissed. .